Why the hell bring Islam into it?

we have a huge debate about it in france right now, it's called "islamo-leftist".

https://fr.wikipedia.org/wiki/Islamo-gauchisme

basically they accuse some left people to have been (too) tolerant with muslim people in the name of multiculturalism, leading to being laxist toward ideologies and cultural practices (such as islamic preachers in some mosques) that lead to / encourage to terrorism (a lot of the terror attacks we had came from people visiting the same mosques..).

it's not completely unfounded if you know some french left-wing poiticians

Ignorance. Had they actually applied those "backward Islamic values", they'd be much more advanced. See: Islamic Golden Age.

That is extremely fitting though. Spot on.