I got the same earlier today some one just straight up disbanded the group as soon as the group finder made the group, so stupid...

Why did we get cool downs?

They could stand to refine how the penalty is applied. For instance:

The penalty should not be applied to players when the group is disbanded. If the majority agreed the group wasn't working out then there's no harm, no foul. No punishment needed.

The penalty should apply to someone who leaves the group after the dungeon has officially started.

The penalty should not automatically apply to players who leave during the 1 minute countdown to the auto port that starts when the group forms. However it should use a three strikes approach where if you leave more than three times in under an hour then a penalty is incurred.

The penalty should not automatically be applied to a player who's been kicked unless that player has been kicked an excessive number of times. While true that sometimes people can and will kick for little to no reason, sometimes people are kicked with very good reason. If a player has been kicked over five times in an hour it's highly suspect that they're doing something wrong and a time out to get themselves together would not be totally uncalled for.

On that note, if a player has left or been kicked from a group the group finder should not place that player back into the same group unless there is absolutely no other eligible player to fill the position (and even then it still wouldn't really be a good idea). After all the group booted them once already, it's doubtful the reaction would be different if they came back.

It would also help if they better defined just when the dungeon starts and ends.

In my opinion the one minute count down to the forced port should be a grace period. Your last chance to decide if you want to stay or go. The dungeon should not be considered officially started until everyone is inside. That should be the point of no return, where leaving incurs a penalty.

The grace period and port should not start until the group is fully formed. Once four players have been matched together and the countdown begins, players should be allowed to vote (up to 3 times) to extend the countdown by another 60 seconds in the event something should come up. If someone should leave the group before the countdown is finished the timer is stopped and the group is automatically entered back into the queue.

At what point the dungeon is considered done should fall under the same guidelines as the silver pledge. With some Bosses being mandatory and some being optional. The mandatory bosses must be defeated in order to clear the dungeon. Once that's done players should be allowed to leave freely.