I think a better topic would be to discuss how 2.X design was better than 3.X and 4.X design. Because I played a few <50 dungeons while leveling my war these last few days and it struck me that

1) some <50 dungeons are actually more interesting and challenging than most >50 dungeons, and were more than just a few trashs mobs in a corridor then the streamlined boss design we have now,
2) tanks actually have to handle tanks mechanics (such as grabbing adds quickly, moving the boss around depending on mechanics, knowing which trash pack to pull) and aren't just subpar DPS who cast mitigation cooldowns to handle generic tank busters.

I mean, I hadn't done dungeons like dzemael darkhold in a while, and the shift in design is really noticeable. One may only wonder why was the game's design so streamlined after 3.0.