As most have recently stated it is a learning curve for alot of people. People are still stuck in their old ways and get worried when things aren't going to plan and look for escape roots out.
I've now gotten to the point of running heroics the same i did in Wotlk which is just Feral charge, barkskin, swipe! demo roar. No CC needed for any pack on any instance and our group really has no trouble apart from some mobs tearing melee a new one with aoe dmg. Although i've come to use cd's especially barkskin on every pull but im sure everyone is getting used to that. I'm not sure if this is a gear thing or not (170k hp buffed 31% dodge) but i'm sure its only a matter of time till people get the hang of how things are meant to be in this expansion.
As for the str/agi thing 1 or 2 items wont break you tanking. I'm still using str neck and weapon simply i haven't come across any better and they do the job fine.