The aura surrounding Myanmar's most famous daughter has dimmed in recent years.

(CNN) -- Having endured nearly 15 years of house arrest with grace and courage, Aung San Suu Kyi has earned a reputation throughout the world as a political superstar of rare moral stature.

But for some, mostly from outside the country but also from within, the aura surrounding Myanmar's most famous daughter has dimmed in recent years.

"I think everyone agrees now she has been a disappointment when it comes to human rights promotion," said David Mathieson, Human Rights Watch's senior researcher on Myanmar.

The Nobel Peace Prize winner's glittering international reputation means that visiting dignitaries still clamor for a meeting since she emerged from detention in 2010 and set about pressing her case to become the next president of post-reform Myanmar. "Everyone that arrives in Rangoon (Yangon) expects to get a photo op," said Mathieson. "They all want that Suu Kyi photo on the mantelpiece."

But for some observers of Myanmar's emergence from nearly half a century of authoritarian military rule, the 68-year-old's perceived failure to speak out against rising violence towards the mainly Buddhist country's Muslim Rohingya minority is grounds for criticism.

HRW executive director Kenneth Roth was withering in a recent report: "The world was apparently mistaken to assume that as a revered victim of rights abuse she would also be a principled defender of rights."

I think everyone agrees now she has been a disappointment when it comes to human rights promotion
David Mathieson, Human Rights Watch

Aung Zaw, editor of Myanmar news magazine The Irrawaddy, said that while she remained popular among Burmese, Suu Kyi had eroded some of her domestic support in recent years.

Her failure to speak out on ethnic issues and the communal violence that had wracked the country was "shocking," he said, and had been met with disappointment in quarters of the country's ethnic communities.

"People expected her -- as she is a Nobel Peace Prize winner -- to say a few words to stop the bloodshed," he said.

Ethnic conflict has been a recurring feature of Myanmar's political landscape since it gained independence from Britain in 1948.

But following the 2011 transition from military rule to quasi-civilian governance, the country has witnessed a significant spike in violence targeting Muslims, with Buddhist extremists blamed for fanning the flames of hatred.

The Rohingya -- a Muslim minority concentrated in impoverished Rakhine state in the west of the country -- has borne the worst of it, prompting the U.N.'s Special Rapporteur on Myanmar, Tomas Ojea Quintana, to declare this month that the recent persecution of the group "could amount to crimes against humanity." Myanmar presidential spokesman Ye Htut told CNN the government rejected the remarks.

Myanmar's most persecuted minority

The Rohingya -- regarded by many in Myanmar as interlopers from neighboring Bangladesh -- are de jure stateless due to their lack of official recognition as one of the country's 135 ethnic groups. During the controversial recent national census, the country's first in 31 years, officials forbade respondents from identifying as Rohingya, drawing international criticism.

The Rohingya face "very, very strong" antipathy throughout the country, according to Georgetown University expert David Steinberg, being subjected to restrictions on marriage, employment, health care, education and movement, and are the only group in the country barred from having more than two children.

I am not condemning because I have not found that condemnation brings good results
Aung San Suu Kyi

In 2012, outbreaks of communal violence in Rakhine -- home to an estimated 800,000 Rohingya -- left hundreds dead, the majority of them Muslims. The bloodshed displaced huge populations from their homes into squalid camps, where 140,000, mostly Rohingya, remain, completely reliant on humanitarian aid supplies that are increasingly being restricted.

Last month, Doctors Without Borders -- the largest NGO healthcare provider in Rakhine -- was banned from operating in the state, where it had worked for more than 20 years, because officials accused it of providing preferential treatment to Rohingya. Weeks later, international aid workers were driven from the state during rioting by Buddhist-led mobs angry at the aid workers' perceived support for the Rohingya, a development Quintana warned would have severe consequences for the 140,000 within the camps, and 700,000 vulnerable people outside them.

The killings have persisted as well, according to reports. The U.N. says that in January, at least 40 Rohingya men, women and children were killed by security forces and civilians from the Rakhine ethnic group at a village in Rakhine state called Du Chee Yar Tan. An official inquiry by Myanmar's government found no evidence to support the claims of a massacre, said Htut.

While Suu Kyi -- who, through her staff, declined to comment for this story -- has joined rights activists in criticizing the two-child limit for Rohingya as discriminatory, her critics say she has been less than emphatic about the communal violence that has disproportionately affected the Rohingya.

When drawn on the Rohingya issue, "The Lady," as she is known in Myanmar, has consistently hewn to familiar talking points: stressing the rule of law and a commitment to non-violence, while refusing to condemn either side -- a position that many rights activists find untenable.

She has rejected the HRW's characterization of the situation as "ethnic cleansing," and told an Indian television interviewer in 2012not to "forget that violence has been committed by both sides." "This is why I prefer not to take sides and also I want to work towards reconciliation between these two communities. I'm not going to be able to do that if I'm going to take sides."

In November, she told an audience in Sydney that "what people want is not defense but condemnation. I am not condemning because I have not found that condemnation brings good results."

Silence is not remaining neutral. It's giving a green light to those who want violence, keeping this climate of impunity and insecurity
Chris Lewa, Rohingya advocate

Suu Kyi's stance, said Chris Lewa, director of Rohingya advocacy group The Arakan Project, was "very disappointing," in that it falsely equated the suffering of Buddhists and Muslims in Rakhine. "Silence is not remaining neutral. It's giving a green light to those who want violence, keeping this climate of impunity and insecurity."

A 'politically calculated silence'?

So why has this outspoken defender of human rights seemingly lost her voice?

It is, says Mathieson, "a politically calculated silence" that reflects the re-entry of Suu Kyi and her National League for Democracy into the political fold in earnest.

The former political prisoner, who described herself to CNN last yearas having "been a politician all along," has repeatedly said she wants to be the next president of Myanmar. The 2015 general election will see her compete against the military-backed party of President Thein Sein on one flank, and hardline anti-regime activists on the other.

"She's playing a different game now," said Mathieson. "People still see her as this great Nobel Peace Prize-winning icon for human rights and democracy -- what they don't get now is she wants to be a politician taking on one of the most brutal militaries in the world."

Mathieson said Suu Kyi's political fortunes depended on negotiating several challenges, including trying to strike a balance between international expectations -- "most of which are outlandishly unfair and ill-informed" -- and a "very complicated domestic setting where if she suddenly did do a volte-face and spoke out on behalf of Muslims, it would be politically disastrous."

Moreover, she was operating in a complicated post-authoritarian domestic environment in which she had opted to work inside the system as a lawmaker and was compelled to keep senior military figures, who still hold a strong grip on the reins of power, onside. "I can understand why she's walking on eggshells," he said.

The regime is clever at using her political legitimacy to advance its goal to legitimize its rule
Aung Zaw, editor, The Irrawaddy

Suu Kyi's political ambitions were complicated by the fact that a clause in Myanmar's 2008 military-drafted constitution prohibits anyone with a foreign spouse or children from becoming president, said Mathieson. Suu Kyi's late husband was a foreign-born Oxford academic, and her two adult sons are British.

While Suu Kyi and her supporters are seeking to have this clause removed from the constitution before 2015, the time frame to achieve this is short, and parliament has indicated any changes to the constitution would prioritize other reforms first.

For some in Myanmar, it is her perceived failure to successfully negotiate her new relationship with the military that is the biggest source of disappointment. To Zaw, her accommodations to the military establishment have led to her, and others in the opposition, being co-opted by a "completely flawed system."

"Her reading of the government, an offshoot of the repressive regime, has been wrong," said Zaw, citing her controversial support for a Chinese-backed copper mine in Letpadeung, which saw her sharply criticized by local residents opposed to the project, as one such misstep to have alienated supporters.

"The regime is clever at using her political legitimacy to advance its goal to legitimize its rule, and to change the perceptions of Western governments towards the country -- from pariah to darling of the West.

While she retained popularity among many Burmese, he said, the result was that Suu Kyi had lost some of her allies "inside and outside of Burma."

'Not so simple'

But others are more forgiving of her position. Influential blogger and activist Nay Phone Latt, who was a political prisoner for four years under the junta and is currently campaigning against a wave of "hate speech" in Myanmar, stressed that Suu Kyi was negotiating a complex political environment at a critical juncture for the country.

"The political situation (in) our country is not so simple," he said. "I don't want to blame her."

I think she thinks she's the person in that country who best understands what democracy is about, and what's best for the future of Burma
David Steinberg, Georgetown University

Steinberg said he interpreted Suu Kyi's politically expedient stance on the Rohingya issue as motivated out of concern for Myanmar's national interest, rather than being a purely self-interested act.

"I think she thinks she's the person in that country who best understands what democracy is about, and what's best for the future of Burma."

He believed that Suu Kyi remained "very important" to Myanmar's future, but that her significance would diminish over time, if the government's rapid reforms of recent years continued apace and brought about significant change.

"If the government can deliver improvement in the lives of the people, if they do things with the environment and pay attention to minorities, then her status will quietly diminish," he said. Suu Kyi would likely retain a high profile to the rest of the world regardless, he predicted, "because we like Joans of Arc."

For Zaw, despite his criticisms, Suu Kyi remained "one of the hopes in Burma," alongside "many other democrats and ethnic leaders who continue to push for genuine change."

She retained the support of many, he said, and crucially, she was not corrupt.

"I still think there's time for her to change her tactics, reconnect to the roots and rebuild her base," he said. "If she can mobilize people and her allies, inside and outside, the other side will negotiate and make more meaningful concessions.

"She is someone Burma was expecting for many decades. She should know that the country needs her."