Things like this make me wonder as if there are truly any people out there that are on the middle ground in this fiasco of sorts?
I truly feel that both sides have their merits, speedruns are causing people to not enjoy their first time in dungeons and thus causes group disruptions.
However, on the flip side you have the fact that you do have to run these exact same dungeons multiple times, causing it to become excessively dull and repetitive. If you can make an hour long run in twenty minutes, then do as such.

However, I know for a matter of fact, that as a tank I am in part responsible for dungeon pacing and how we'll tackle it, I know for certain that for my FIRST run of a dungeon, I will be sure to experience it to it's fullest, ignoring the barraging behest of those who wish for me to skip cutscenes. However, for any SEQUENTIAL run beyond that point, I'd be sure to do it as fast as I can as I have already seen what the dungeon fully has to offer, so what reason for there would be to experience something a second time? At that point, you can simply rewatch it in the Inn.