Tebow is a reincarnation of Rex Grossman. Grossman is another Florida product who won games, too. He took the Bears to the Superbowl in 2007 during a season which saw him turning in as many games with a 100-plus QB rating as he had games with a sub-50 QB rating. The difference between the two is that Tebow turns in far more bad performances than good. That's why Grossman is still 3rd stringing it with D.C. while Tebow will be out of football in a couple of weeks.
Tebow is being punished for being a devout Christian, not because he can’t win football games.
He's being judged by his skills as a quarterback, which aren't overly impressive.