Without that command, races who leave no corpses, are easily full looted/full sacrificed. I believe it has been implemented exactly for that particular reason, so that you won't be able to destroy everything an undead had when his corpse desintegrates in one tick. It does not prevent people from simply typing "get all" and full looting the undead/vampire/lich though, so maybe that needs some extra toughts. I agree about the corpses though. Shouldn't be lagging there. And maybe I should make it clear that I am posting on the forum to try and make suggestions on how to improve. I am in no way playing, nor will I ever.
Explanation for those who think I've changed my mind yet again and gone back on my word.