There should be more than one way to gain XP (experience) in defeating a MOB. A defeat should include either: killing the MOB, forcing the MOB to flee, incapacitating the MOB (knocking them unconscious counts, sleep and hold spells do not). That is because it is insane to say that a hero is Angelic for slaying 5000 MOBs. Good generally frowns on violence, even when necessary. Evil is that "quick and easy path" that glories in violence and disregard for life. Yet alignment on most MUDs depends on the alignment of the creatures you kill. Think about it--an evil creature can kill other evil creatures (a rival perhaps, or maybe for sport) and STILL BE EVIL.
Yes, incapacitating or staring down MOBs is harder, but that is the point. Good is hard, evil is easy. Yet if you make good rewarding it will still be a challenge that many players will enjoy. Hack'n'Slash is too limiting, and gets old real fast. Evil acts include killing, casting harmful spells, etc. Good acts include certain rituals to cleanse oneself of impurity, or quests to please certain deities.