They really need to start banning them. I main a PLD and it sickens me when this crap happens if I'm on another job. It's incredibly rude and needs to be punished.

My suggestion is this: Allow two withdraws from queue. On the third strike, the person withdrawing takes a 30 minute penalty. It then also flags the system that said person has received the withdrawing penalty. Once that person receives 3 flags, they are then banned for a shortish period of time (say 3 days). Then it will progressively get longer.

Keep in mind, I'm talking about withdrawing from the queue, not once you've entered a dungeon (which there's already a penalty for). If you've ever had it happen where your queue pops over and over for short periods, it's a Tank constantly queuing and withdrawing trying to get an in-progress dungeon so they can more quickly get their Myth tokens.