Seems to me that there is plenty of valid criticism regarding MT. Whether one is a "believer" or atheist it should be clear that MT wasn't the shining example for humanity that many believe. Did she do good? Yes. But shouldn't she be measured by what she could have, should have done? Let's say she did do good, but was it possible for her to do better? Seems that way.
And if it turns out that someone has rather twisted views and motivations it can hardly be character assassination to bring that to the fore. Some criticize the college atheist group for their stance, but it gives people the opportunity to look at the bigger picture and hopefully get rid of some illusions. I wish people would learn to be more sceptical and take a closer look at seemingly noble public figures. They seldom deserve the hero worship they get.