I'm guessing the agenda is "this is definitely going to lead to a bunch of anti-islamic discussion in the comment section, and I don't want to deal with all that (with limited mod tools)"
I'd put more blame on reddit administration than the mod who's trying to play the safe side to keep the sub in existence.
Different subs get different rules, unfortunately. The anarchism sub was constantly being threatened with being shut down if they didn't self censor stuff that was fine anywhere else in Reddit, for example.