For me its even simpler than that: he's bad and he knows it. I wanted to believe in Tyrod and did for a long time but I'm not going to believe in a guy to come through with huge improvements when he doesn't seem to believe in himself.
I think the consensus on Tyrod will continue to fall until he's considered a bad starter / strong backup. That puts his value well below his cap hit and calls for a release. Just my take, Marty, I'd rather Romo or Foles as the bridge guy and run a more well-rounded, more modern offense, supporting Shady and Mike with a legitimate passing attack, getting more out of Watkins and Clay.