Unfortunately, tanks also exercise the same amount of power, especially in later dungeons. I would hesitate before actually telling the other party, "let me watch my cutscene or gtfo" as that is the same as your tank saying "skip the cutscene or gtfo". Both burn bridges, and I'd hate to be caught between 2 equally stubborn players over something as stupid as watching a cutscene.

On a personal note, I agree that if a person is playing a dungeon for the first time, let them watch the cutscene though.