I could be wrong, but I think part of the idea of randomly generated dungeons is, besides replayability, is that your experience will be different than your friend's experience so you can stand around the water cooler comparing.
EDIT: Since sooooooooooo many people found such fun in nitpicking my response apart, let me clarify that I'm more referring to how the randomly generated dungeons change one's gameplay experience. Those would be worth talking about with your friends. Also bearing in mind that it's not just the dungeon layout, but the monsters and, to a limited degree, the quests as well that are randomly generated.