anyway there are wackos everywhere but if a wacko happened to be born in a muslim country he would be always recognized by Western media as a muslim wacko
I'm neither Christian nor Muslim and feel free to criticize all wackos regardless of religion.
One crucial difference, with your example. The crazy people that killed their babies and froze them were not claiming to act on Christian principles and when crazy Christians (like Fred Phelps) do crazy things, there's no shortage of Christians publicly denouncing them. Too many terrorists claim to be acting on Islamic principles as do too many purveyors of other social ills (like honor killings). But too many Muslims (who are good people) are too hestitant to criticize crazy Muslims in public.
This is maybe partly because this is because Islam stresses a private conscience, micromanaging the adherents daily behavior, while not acting against social ills that cannot be addressed through purely religious principles.
It also might be partly because Islamic practice doesn't recognize social groupings beyond the family AFAIK. There is the individual, the family and the only social division recognized in Islam is between Muslims and Kufar.