I think they are very troublesome, but if they do ban them it'll make them look bad because the christians will think the "atheists" won. I think the current system of locking/deleting them when a flame war starts is good. You just cannot control some members tempers, and that's the issue. It's not a debate, it's mere arguments.
About political, it's less of an issue than religion on the base it seems. It can stay I guess.
Personally, I could care less if they go or not. I guess I'm in favor with you, but it won't happen.