Yeah, I don't follow wrestling much anymore, but Miz is essentially some random dude who got cast on the Real World and somehow through charisma, hard work, and a little luck has turned himself into a mainstay in the WWE, made himself a convincing (if not exactly fear inspiring) heel WWE champ, headlined WM with Cena (and got the win I might add)...it's really ridiculous when you think about it. I actually agree with him getting pissed off at Bryan though, it's like he's looking down on Miz for not having the indy background. He did it a different way, and although I think being in the main title picture was over his head, he made it work for quite awhile.
Him pointing out the injury thing is just funny, he's not wrong either. Some guys just go out and hurt themselves a ton. Frankly it's not good for business. Sometimes they're fluky things, but some guys just do a style that is going to lead to them being out almost more often than not.