Any solution needs to be cost effective.
1) Make a list of the idiots who are doing this and we will just DELETE all their stats.
2) /kill is hardcoded into the game. It would cost me hundreds of dollars to get rid of that. Besides, we have slay commands that force clients to kill themselves when they get caught glitching or doing other stupid stuff.
3) An alternative plugin would be to have B3 read the log for those who killed themselves and were not slain, then some punishment would be given, like a tempban of X minutes.