Tebow is far better than half of the 2nd string quarterbacks in the NFL right now.
IF the Broncos had kept Tim Tebow, I am sure that the Broncos would today be Super Bowl Champions.
Difference is the 2nd string QBs have all been in the NFL for the required time that they get retirement. So it does not cost the Cowboys to have Orton as a back-up. The team that has Tebow at a certain tenure (I think five years), they are responsible for his retirement. No team wants to have that liability for a professional second string QB. In the NFL, you either make it in five years or you are down.