I feel like I know the problem, but I don't have a solution to it because it involves the attitudes of players as a whole.

There always seems to be a conflict of interest between new players and veterans. Veterans have seen the content repeatedly and simply want to plow through it as fast as possible to get it over with, but new players typically want to experience everything the dungeon has to offer. This can create frustration on both sides as neither of them can have a fully enjoyable experience due to each other's conflicting goals, made worse by the fact that often times, especially by mentors, there is very little team communication going on.

I'm sorry you went through this situation, yet at the same time I feel like I understand the other side a little bit. I think it's a sad reality that many people simply don't have the patience and/or temperament to really help those who are struggling with the game, especially when their goals particularly involve "get in and get out."