yes criticism of islam has become very complicated
If we need to be careful when criticizing Islam, it's because racist shitheads love to interpret any criticism against Islam as a validation of their generalized hatred against all Muslims.
it should be noted here that post-9/11 "muslim" became an extremely racially charged word in the west that basically denotes "scary foreign brown person". that's probably really obvious but bears repeating because of the "duh muslims aren't a race" argument torchkas mentioned.
that said, there were/are definitely people on the left who romanticize the "anti-imperialism" of radical islamist groups (not so much now anymore with ISIS being so obviously terrible) and there are also points to be made about well meaning white liberals handwaving the issue of radicalization.
what i've noticed about the immigration and multiculturalism debate in my country is that it's mainly led by privileged white people (like me lol). the right is outright hateful and bigoted while the left is often patronizing. the people actually being talked about (immigrants/people of color) don't get a lot to say in this debate and often seem to be treated like an amorphous mass for aforementioned privileged white people to project their ideology onto.
tho, looking around me, i don't think the west has a problem with being overly accepting of radical islam at the moment lol.
so yeah, like i said: COMPLICATED