Far from exclusive to islam, but it's certainly socially acceptable and often condoned in many muslim-majority cultures and countries.
The only people who would say it's okay in one country and not okay in another are moral relativists and those who view law as the authority for morality. Off the top of my head, I don't know any liberals who would defend this. Surely someone, but I doubt any prominent figures would.
As for "how they can justify bringing people like that over," that's just silly... I'm not even sure where to start breaking that down. A combination of islamophobia, composition fallacy, strawman, western exceptionalism, a dash of isolationist rhetoric,... You've got a lot to sort out, and probably shouldn't yap about foreign/immigration policy until you do.