I have a suggestion for what I think would hopefully solve the quitting problem. I hate habitual quitters, yes- but sometimes there are good reasons to quit, and sometimes those reasons can occur multiple times in a short period. Here's my suggestion to (hopefully) make everyone happy:
1. During any team game members can access a 'vote to surrender' option under the start menu. If every single *remaining* member of that team surrenders, they lose, the game ends, those players have no penalty.
2. If a player quits any game of any type for any reason then he/she cannot join a new game until that old game has ended.
3. If a player quits a game, then shortly after the remaining players veto to surrender, then the first player who outright quit will not be allowed to join a new game until the timer WOULD have expired if the team members hadn't surrendered.
4. The 'vote to surrender' option for FFA applies only if all players vote, not all team members since each team has only one person. In this case, the match would be a draw, not a loss.
Re-read those a few times. I think it would cover all the cases:
Habitual quitters could still quit, but would gain nothing from it, and would spend most of their time just waiting around in the lobby if they really just wanted to ruin games. Also, they would get no credits/exp/whatever, so there's no incentive for them to continue.
If someone REALLY doesn't want to play a game then suck it up and deal with it- unless your whole team agrees. Then, the whole team can vote to surrender, the other team gets points, no ones time is wasted and everyone goes home happy.
Say it's CTF 4 v 4. If one team player quits and it becomes 3 v 4, then that quitter gets no exp and has to wait til the game ends to move on. If the remaining 3 members then decide they don't have a chance to win and want to quit, they can vote and not have to wait for the game to end. They still get whatever credits they would normally get for losing the game. The quitter has to wait the 12 or so minutes until the match otherwise would have ended.
If someone quits immediately then the punishment is more severe than for someone who quits with 2 minutes left. I think this is fair.
If someone's internet habitually lags out, then that sucks, but odds are they will take a few minutes to get back online anyway, so they won't really have to wait around for very long- especially if it's in the beginning or near the end of a game.
If you quit a single game because you need to go somewhere/do something, then odds are that something will take more than ten minutes if it's urgent enough for you to quit. You will receive the 'quitting punishment' but since it applies only to that game you won't even notice or care.
This system could be applied to everyone, so no one would have to be 'soft banned' or labeled a 'habitual quitter.' This might make those with laggy internet feel less like they are being negatively labeled.
I think I've just about covered everything here. I hope someone reads and considers this- I think it could work out very well for the community. Also, excellent job so far on the Beta, Bungie! You guys rock!