It's not just Muslims that are fundamentalist extremists. But of every major religion, Islam has the highest rate of that kind of extremism. There are plenty of Christian countries which are socially progressive and endorse modern sensibilities. No Muslim countries are.
I have a dear friend of mine who is a religious minority in Egypt (she's a Copt). The paranoia that she and her parents have when interacting with Muslims is saddening, because of how it's been justified. Her church has lost several members to religious violence, and she's lived through a suicide bombing which happened at that church and targeted Christians.
I'm not saying there aren't Christian extremists. There are. But the Muslim extremist problem is an order of magnitude larger within that faith.
Judge individual Muslims for their own beliefs. But there is no Christian version of the Taliban state or ISIS. And Islam is to blame for the actions of its extremist adherents writ large. It desperately needs a religious reformation, but instead, the Saudis are still chopping the heads off of people who offend their religious police.