While I hate queuing for 20-30 minutes, only to find out that the tank is a fake tank, thus rendering the last 20-30 minutes an utter waste of time, I sadly have to disagree. But only because I fear the alternative. People quitting out of frustration, or using dungeons as a time filler until a spot opens in a trial or other dungeon, or people who just want to farm for gear bailing out too soon would be more prevalent. There has to be something to encourage people to stay in and stick with it.

You could even put the DLC dungeons aside and use vet Banished Cells 2 for an example That final boss is brutal. I have yet to be in a group that burned him down in hard mode without it taking a considerable length of time, at least in comparison to most other final bosses. Allowing people to quit, likely mid-fight would hose the rest of the group. Its one think to kick someone, its another to allow people who need instant gratification to bail at the first sign of trouble.

Sounds like a good idea, but i feel like there should almost be a thing to ask you why you left the dungeon and the game could check to see if there was an issue. I know it's a little excessive, and maybe crazy. I almost always play as a tank or healer, so i do get upset when the dps in a dlc dungeon are like cp 70, even when i did a specific search.