There is no "hypocrisy" with Cena though. He was a full-timer for like 15 years (which is longer than Rock and Lesnar btw) and, whatever issues they had with booking him, busted his butt all that time and worked really hard. Also he would even come back from serious injuries quicker than many other men would. So now that he's nearly 40, and has been dealing with yet more injuries, he's starting to transition to part-time status (and he's still more consistently involved than Rock or Brock are even now).
If anything Ambrose comes across like a petulant fool who doesn't pay attention to the recent history of the company that he works for.