The way I see it people want speed runs because the dungeon gets mind numbingly boring after the 501390th run. They just want to get it over and done with. Whether it is because they have to do their duty roulette daily, leveling up a side class, farming tomes, or getting that item drop. When you know you can do the dungeon once any satisfaction of completing it more is very minimal.

Of course this doesn't excuse their behavior. If someone wants to watch the cut scenes then wait 10 freaking seconds and let them watch. If someone doesn't want to speed run then it shouldn't be forced. If you are voted out because your opinion differs then you are reminded of how democracy works.