It's not a bug. If OP isn't exaggerating and there are literally 30 people there, and they're telling them all to wait instead of breaking into groups for the people who have to leave, then they're idiots.
I suspect it isn't actually 30 and there are a handful of low level players that are there, and that's why they don't want to break out til they know they'll be fine.
I lead a lot of raid groups, and frankly the ones who are the least level-headed are the ones who HAVE to be in and out in 5 minutes. They also expect to be waited for. They also tend to enjoy things the least, and don't get invited to raids in discord.
If OP wants to get out of there, he needs to find out how many are willing to wait for group 2, ensure that that group has enough on its own to win the raid, then break up his group by team with the minimum that will be necessary to win the raid allocated.
But if he's ranting on reddit instead of actually doing this, then he's probably just that guy who sits in the corner grumbling about having to wait without expressing to anyone that he has time constraints. I hear these people all the time, and if they don't have the testicular fortitude to tell people that they need to be somewhere, then 'somewhere' probably isn't that important to them.
One day maybe ill get around to doing a comprehensive guide on raid etiquette. There's a right way and a wrong way to handle these kinds of situations, and he picked the latter.