What more would you have the Jets do for him? They've already given him top notch defenses and running games in his first two seasons. He sucked when he had those things and he still hasn't gotten better two seasons after that. His age is irrelevant, if after 4 seasons of trying to improve the very same occupation, and you have not, you would be FIRED. That's reality in any occupation that you go into. That's called REAL LIFE.
Is Mark Sanchez a great QB? Has Mark Sacnhez won two SB's?There's no comparison whatsoever, and for that matter, there's no other team that you can compare to the NYJ. EVERY team has a different situation and therefore it must be treated differently.
And once again, the team would not be giving into what the fans want. Rex would be doing what he must do in order to shake things up and create a better product right now. That also happens to be what the fans want. So by accident, it would appear that Rex was being loyal to winning and the fans.