Tebow can't throw.
So I give some credit to Ryan/Sparano for limiting his time on the field. How the hell do you use a QB that can't throw? It's just like Miami trying to "use" Pat White. If the guy can't throw, you can't get him on the field.
Tebow can throw in certain situations...see the game against the Steelers.
But more importantly IMO Tebow can be a very dangerous red zone weapon running the ball. The Jets really haven't used him in that role, which is a big surprise to me. He was dominant in the red zone with Denver.