Killing a character because the person left the RP would be assholish, and I don't agree with a motivation of 'CHARACTER DEVELOPMENT', given that people have known the character for all of... maybe an hour or two. It'd be forced and ridiculous. 

Plus killing characters like that is slamming the door in the player's face in case they ever decide to rejoin. Doing that because it gives people a chance to write ANGSTANGSTANGST is wrong. :/