Numbers
The hard fact remains that, here and now, radical Muslims are committing religious-based violence in numbers that dwarf every other modern occurrence of ethnic violence.
More civilians were killed in two hours on 9/11 than in 36 years of Irish violence. Go down the list of current wars, and see how many involve radical Muslim aggression.
The reluctance of liberals to correctly identify the problem is so great that I figure some basic paradigm is being threatened, but I have yet to figure out exactly what.
Don't know why SDF or anyone else would drift off into a general anti-religion thing. Much of what radical Muslims believe as far as how society should be organized isn't even in the Koran, but based on Arabic cultural norms.