Aw! I play almost no video games, but I know what you mean. It's like "If they're such sweet people, shouldn't they be more hesitant about killing, or at least killing people?" (It's a bit difference when the enemy is a zombie or non-sentient alien or demon or something.)

...are the games definitive on the "punched a guy to death" thing, or could it be interpreted as punching them into unconsciousness?