I was not talking about exactly that, class balance was always harsh for us. I was more talking about things like: failing 98% success 4000 gold BLingtron mission; getting from coin warforged socketed versatility gear, seeing ABSOLUTELY NO FREAKING socketed tier pieces - simple things like that. You won't argue that Blizzard are piling way more rng-based elements of "gameplay" in WoW than they should (and way less skill-based ones).
Well, it definitely would be hard as hell to play unmobile shadow priest with almost no meaningful instants, that's for sure. I started playing CoP when dinged lvl 100, and then switched to AS in BRF, and had like two weeks of struggle because of making my muscular memory actually understand that I can't cast mind blast when I move.