Why havent Fundamentalists learned that Blind obedience and Ingroup is dangerous?

The fundie christian mindset is essentially the same as the Islamic fundamentalists, only difference is one is christian and the other is Muslim. Fundie christians occasionally DO commit acts of terrorism, shootings and murders in the cause of their faith, but these acts usually get disowned by other fundies who say "oh, we don't shoot up abortion clinics, that's not what we really believe in."