Should level-capped players be put into content they outgear?

I do not like The Stonecore.

On a recent guild-sponsored alt run, four not-ready-for-heroics players and my level 85 shammy queued up for a random Cataclysm dungeon. We wound up with The Stonecore. We immediately decided that we didn't want to run The Stonecore, but we also didn't want to just wait the 15 minutes to requeue. So, we cleared our way to the first boss and defeated it, successfully eating up the 15 minutes.

Not wanting to actually finish an instance that didn't offer us any level

World of Warkraft...