Well, we still have an easy solution for those laggy games, or games where half your team quits. Just have a computer/laptop handy, set the controller down, and go on the comp while you wait for the match to finish.
So from there, will Reach kick out AFK'ers (Away From Konsole, better known as A Free Kill)? Then tape the thumbstick down while you're AFK. What about the players who grab the power weapons and jump off cliffs?
It's not possible to effectively weed out every d-bag type player on Live, and trying to deter quitting is a bad way to do it. Instead, if one person on your team quits, which actually causes your team to be unable to win, there's no sense for everyone else not to quit as well. In that case, everyone on your team gets that little stats penalty, the other team wins, and life moves on.
Also, Matchmaking will inevitably pair a team of MLG players vs. a team of those who just bought the game, or someone will have a severe host advantage due to shoddy internet connections. This happens more often in Halo 3 than you may think. Again, having the hopeless team quit and loose a little XP is better than wasting time finishing the match. The losing team benefits from being able to hop back in and try to get a legit match, while the winning team doesn't waste any time getting easy kills on AFK players.
In many cases, quitting is not just the best option, it's the only good one. The quitting ban discourages it in these cases and makes annoying situations of bad matches even worse when people are afraid to drop out.
Here's an idea: auto team balancing. If two players on one team drop out, the lowest performing player from the other team gets moved over. Simple as that.
Also, if the quitting penalties apply to FFA games, that makes absolutely no sense at all since no one is "hurt" by those quits. There was no mention of this in the update so I'll assume that it does.
In the end, people who have to wait due to the quitting penalty will probably just hit eject on their system's disk drive and play something else until it's over.
[Edited on 05.14.2010 5:51 PM PDT]