Excluding communities simply because you feel like theyʼre unclean is so… boring. Like, we as a species have done the whole / “racial purity” / “religious monoculture” thing for thousands of years now. Excluding people for non-violent reasons doesnʼt give you an advantage; you just get left behind as people with new ideas get poached by inclusive tolerant cultures that are intolerant of your intolerance. You can try to raise the switching cost by building walls and making emigration illegal, but sooner or later you get invaded; at best you get ignored and stagnate, dying an early death from silly things like tooth decay because you chased out all the dentists.