I think that the "no true scotsman" fallacy should be renamed to the "no true muslim" fallacy because that is literally the first line of defense against any sort of statement that implies that, perhaps the mass exodus of people from the middle east isn't a good thing.
I don't see what the alternative is. Imagine for a second that you live in Mosul with your wife and three kids. Your local CIA-controlled government is cracking down on apostates and, for all you know, your family might be next.
Does it really matter to you whether the Middle East is going to suffer in coming decades because of the depopulation? Does that larger context really make any difference on a personal level?
"Oh he wasn't a REAL muslim, he drank alcohol!" or "he was depressed/self-hating because he was bullied by mean westerners for his religion!" or my favorite one, "the motivations are unclear/hard to unravel (despite the attacker having shouted "allahu akbar")
I mean, I'm sure people say those kinds of things, but that's not really the primary school of thought among liberals.
In American politics, it seems like the two competing explanations for the crCIA in the Middle East are as follows:
1. The Middle East is a violent, unstable hell-hole because there's radicalized Muslims. There are radicalized Muslims because Islam is an inherently evil religion.
2. The Middle East is a violent, unstable hell-hole because there's radicalized Muslims. There are radicalized Muslims because the region is controlled by insurgencies which fed upon anti-American sentiment in the wake of the Iraq War and were allowed to proliferate in a US-created power vacuum.