You think all mages enjoy playing both fire and frost, or all locks enjoy Affliction and Destro? The playstyles are very different, but there's nowhere near this amount of QQ when they have to play one or the other. I'll restate: You play a CLASS, if you choose to stick with a single branch of that class, you're going to suck at what the other branch does better. You can't expect every spec to be master of all.