There was some speculation that Chris Hero, formerly known as Kassius Ohno during his time in WWE NXT, may have been released from WWE after complaining about his spot in the company. However, it's now being reported that this is simply not true, and that Hero was never really one to complain about anything during his time in NXT. In fact, it's said that Hero was one of the few talents who rarely ever complained about anything.
Regarding who was behind him from a political standpoint, it's being reported that head writer Ryan Ward and even Dusty Rhodes were high on Hero.
It should also be noted though that it was reported a while back that WWE officials were not pleased with Hero's physical appearance, as they apparently felt as though he was letting himself get out of shape. It was also reported that Hero had heat on him with WWE officials for acting as though he didn't care about his in-ring conditioning.
At this point it's uncertain how much of these reports were true. A specific and conclusive reason for Hero's release from WWE has not yet been revealed.