Sometimes assholes are super-productive geniuses (note that there are more assholes who think they're a genius) so even if they don't get along with the rest of your team (or any humans, really) it's a tough tradeoff whether it's worth having them around.

You have to balance whether they're doing more harm than good to the overall endeavor. In our case, we have one very senior guy who's highly antisocial but absolutely a crack dev. We've given him an extremely flexible work-from-home arrangement. It works out well because we hardly see him, and he's happy communicating over email and just churning out code in his batcave or whatever.