To me, there's a pretty huge distinction between being an annoying jerk and roleplaying. The distinction to me is how they behave if they get caught and punished. If they're a corrupt tribunal and they get booted or something, titled, etc and stick it out then that's a good character.

Most of the time you see this though (ie: murder everyone neutral chars), they'll get punished and delete because the reason they were doing what they were doing wasn't roleplay related, it was powergaming related. IE, they were throwing RP to the side to gain some competitive advantage that only exists because the game isn't perfect.