Back to the original post.
I don't say that Buddhists should feel guilty for the crimes of other Buddhists; however, Buddhists should care about the suffering of others and do whatever they can to make things better.
Not feeling shame or guilt about what other Buddhists do does not mean we can excuse ourselves for our own lack of response. It is that lack of response that I am critical of. To simply say something along the lines of: 'Well it's not my karma' is selfish and infantile. I think a Buddhist who only thinks about his or her own Karma has not got very far in their practice.
I feel Buddhists have a particular responsibility to criticise and highlight the bad actions of other Buddhists, otherwise our silence may give the impression that we don't oppose those sort of actions. That is bad for the spread of Buddhist Dharma in general that, at least in the West up till now, has a reputation for peace and tolerance. I think there is a lot at stake for the future of Buddhism and how it develops in the West.
In the same way, ordinary peace loving Muslims are not responsible for the actions of a few terrorists, but the condemnation of terrorism by Muslims helps to conteract those who want to portray all Muslims as terrorists. The same as when Jews condemn the actions of the Israeli govt in respect to the extreme attacks on Gaza, this can counteract the anti-semitism or anti-jewish attitudes that develop. That can help us to see beyond the simplistic notion that the problem is the jews, or the muslims or the Buddhists... the problem is the hateful and violent attitudes and actions in and of themselves regardles of the religion.