I'm pretty sure you have to be champion to be a FOTY and Bendo was the only one to fight three times last year which I'd bet had a lot to do it. especially capping it all off with a flawless performance.
There wasn't any real contenders for it anyways besides Bendo,Cain and Bones. though personally, i would have given it to Cain. the hype behind JDS was reaching mythical levels and Cain downright dominated him.
Breakthrough FOTY would go to Hendricks,Gus or Cormier.