I think if you added up all the people in the US killed by radicalized crazy/evil Christians who killed people for ed up reasons, you would end up with death toll that far exceeds 9-11.
The only difference is that the muslim nutters got lucky and pulled off a single, high-profile event.
The steady drone of cop-killings, shooting rampages, lynchings, and so forth is edited out conveniently for you by your own confirmation bias.
You seem to be conveniently forgetting white christians' terrorist past.
I will spare you from the pictures of various lynchings. They are horrible.
That is just the lynchings. That doesn't include things like the Oklahoma city bombing and so forth.
Modern muslim terrorists simply come from countries with the rough educational and economic levels of the US South of the late 1800's.
I think it has less to do with the type of religion, than with ignorance and extremism.
Terror is terror.