Well, I can understand that it might be frustrating, but you have to see both side of the story for this.
Let me give you an exemple :
- DPS A wants to do a quick roulette because he has to go to work soon after/take care of the kids/whatever.
- After 10-15 min of queue, his roulette pops and he can start.
- But there's a new player so everyone wait to watch the 30+ minutes cutscene (for praetorium, but sometimes people are slow readers).
- DPS A won't get his reward because he will have to leave the dungeon before the end because it will take longer than expected.
Now, when you realize that the majority of player that goes in roulette are like this, you understand why there's a rush.
Add to that the fact that for some of those players, it's maybe the 200+ times they did it, and you can understand why some of them have no patience.
So, do like 95% of the players did, go through it then watch it from the cozyness of your house/inn, it'll be the less frustrating for everyone.