The Miz is by far the most underrated wrestler in the promotion today. Working in reality tv made his mic skills better, because he can easily make people hate or like him (one of the most crucial mic skills needed to do well in wrestling).
He is a good wrestler as well. Not AMAZING as such, but good enough to be high midcard. His WWE Championship reign eventually got ridiculous, but putting a WHC on him would give him a boost. He, by a LONG stretch, is one of the most underrated wrestlers in the WWE right now. He should be competing on Main Event, not commentating on it.