Hows about when you quit, you get a window on your screen where you can give a reason for why you quit, then that reason is in-game mailed to the other 7 ppl that was in the WZ with you, and they in turn have 2 checkboxes, 1 for "yeah this seems legit and I remember that guy, he did good, I'm ok with him leaving" and the other ofc being "hell no, he's an idiot". If you decline to give a reason when you quit, you automatically choose option 2 and get a 6hr ban from WZ:s, but if 4 or more ppl think you're ok, nothing happens. After 2 hours the game chooses option 1 for anyone that hasnt responded to the mail so noone is banned just because a bunch of ppl cant be bothered to read their mail. During those 2 hours there should ofc be no action taken so you dont first get a 2h ban for what turned out to be nothing.
This is probably a crappy idea, because everyone will select "hell no" and the quitter will get the ban 99 times out of 99, but I thought I'd share the idea anyways.