I'm gonna stick my neck out here and say "evil" players are just part of RP, and shouldn't be frowned upon. What should be frowned upon, is non-rp PvP. Someone just running up to you and attacking you is a big let down in MMORPGs today, you wind up with a lot of high level bored players eating younguns, and a bunch of pissed off younguns who can't get any leveling/questing done. Perhaps a PvP based system that was free but regulated by GMs (as per DR) would be satisfactory.
EG: if someone attacks me for no reason, I should be able to report them and GMs look into the issue and penalize as they deem necesary, but if I'm antagonizing someone, kill stealing, pick pocketing, etc... well I guess I deserved that beating.
The whole concept of good vs evil PvP is bland and stale to me. A troll player meets a human player, and kills him, without a word said. These two might have been bosom buddies if they had got to know each other, but because of the "good vs evil" struggle, this is one friendship that will never be.