Religions don't threaten?   That is like saying that the Nazi ideology wasn't responsible for Buchenwald, or that Japanese nationalism wasn't responsible for the rape of Nanking.  Whether the ideology is religious or not doesn't matter; what does matter is whether that ideology promotes violence.

History has proven that mass ideological movements can incite genocide.   Can we supposed to ignore religion as one of those mass movements, just because it's religion?

What is happening with Islamic extremism is directly tied to Islamic religion.    We can't ignore that, nor can we make the argument that religious people of one tradition can't criticize those of another.