I have to wonder (aside from the obvious answer that the hardcore players are just bored and like picking on normal people) why anyone believes any of this "morality" malarky that higher end players use as justification for killing. If you're a bandit and kill for the fun of it, just own up and say you're a bandit and kill people because it's amusing. Trying to pin morals because you found a clue of a crime (which the current system leaves the game completely broken in that regard, tracking a person is an involved process thats currently distilled to a homing beacon) is really pathetic. If you're tracking outlaws "for the greater good", you should take a moment to think about the way legal systems usually work. If a town was raided with thievery scents everywhere and the village chief/remaining people want something done then by all means it's the "right" thing to do (by classical morality), however I've never seen a case where death was an appropriate sentence for trespassing anywhere in the modern world (except for maybe military bases). Even in mideval eras theft was generally punished by amputation of the hand (or in more recent eras fines and/or the equivalent of KOing someone a few times), so this isn't even a proper vail.
tl;dr: Stop cowering behind self proclaimed morality, if you're going to be a killer then be a killer and stop waving pathetic excuses around.