Quitters have been a problem in online games for years.
Winning in Mario Kart DS? Opponent quits.
Narrowly defeating your Starcraft 2 Opponent? He quits.
Etc, etc. Quitters make the online experience worse for everyone.
For the record, I was an amazing snaker in Mario Kart DS. Beat a guy that was like 106-0 in a 3-player round once.
Definitely got disconnected on a lot.