Halo had as many moderators as DS and MK. Neither zone had a steady population of over 50, though. Plus, not many zones would be willing to suddenly hire a few more mods. Not sure if they will even find it "fun" as you say, unless they would enjoy abusing, which everyone does. I'm sure advertising would be a much better alternative than letting a horde of cheaters loose to probably mess up the game experience for other players.