Blizz took the lazy route with most WQs. I agree that the elite ones, profession ones, Kirin Tor ones all worked. Heck, some of the upscaled quests work, too.
But some WQs, and Highmountain was a MAJOR source of this flavor, were just time wasters with no real content to them.
Also the "Kill 20 Harpies" flavor that showed up in Highmountain and Val'sharah could have been cut in half and nothing would have been lost.