As crazy as it sounds, John and Karl were mostly pre-internet. Internet voting pretty much screws up everything it touches.
Drop off the first couple weeks of the season, And Mitchell is straight killing it, and is STILL killing it despite being defended like he is Harden. Simmons is damn good, but no one is riding him in the 4th quarter when the game is on the line. He racks up assists and rebounds, but he isn't "must watch" basketball like Mitchell is. I think if we are looking for a Mitchell comp a great one would be Vince Carter, not because of the similarities of style, but because you might miss something special if you don't tune in. Jazz should get a lot more televised games next year that just weren't going to happen with Hayward as the face of the franchise.
Ultimately I think they split the award between Simmons and Mitchell unless one of them get injured or completely falls off of a cliff statistically.
Oh, and before I forget, you can screw right off, loser.