From the Live Letter today it sounds like they might finally be "fixing" this in 4.2:

Quote Originally Posted by Bayohne View Post
We'll be making adjustments to the main scenario dungeons, so that new players can enjoy them without worrying. It may extend the duration of the dungeon; however, we have increased the rewards as well.
The way I personally read that though is that they'll be forcing cutscenes on everyone (extend the duration of the dungeon) so I have to wonder if it'll just stop people wanting to run it at all unless the rewards are insanely good... the cutscenes are so long...