It's one of the weird artifacts of content being moved from current to a legacy role - players queue for dungeons in the dungeon finder as they're leveling up, only to find that the dungeons have a gear requirement that they don't meet. With the speed that heirlooms and guild bonuses can bring, it's easy to find yourself level 83 and unable to enter any Cataclysm five mans because you don't meet the gear requirements (something because of those heirlooms) and it can be very annoying. But now, there's good news - Ion "Watcher" Hazzikostas recently responded to the idea that those gear requirements could be removed with the stat squish with an affirmative.
This would be a very positive change in my opinion - it was easier for me to just level via quests than it was to try and queue for Cata dungeons when leveling up my tauren. Not that I miss all the dungeons we had back then, but it would have been nice to see a few places.