Doesn't the ELO account for losing games by removing skill points already? Unless I'm mis-understanding AMP I think that the ELO (as implemented in say, chess for example) causes people to lose ranking when they lose. They lose more ranking when they lose against someone who had smaller rank and lose less ranking when losing against someone of higher skill level. The ELO includes that sort of handicapping element already, however, that isn't to say it can't be abused, as is evidenced in other online games which utilize this scoring system where people will create games only play against noobs in order to get a high ranking.

If anything what I would like to see in a competitive atmosphere is the guarantee of sportsman-like conduct. I have found that when people get competitive it ruins the 'fun' atmosphere of the game because they end up resorting to verbal abuse and other non-game related means to win.