Leinart is a very good college QB, along the lines of Doug Johnson or Gino Toretta. I respect his choice to stay in college, absolutely, but the chances of him raising his stock, compared to having it go down, is miniscule.
If he gets hurt, of course, the policy will cover him for a couple million. But not nearly to the extent of the guaranteed money he would command in this draft.
If he has a bad year, nothing is covered. And as ScottUSC mentioned, his tendonitis will become an issue.
I suppose it just comes down to a risk that he's willing to take.
He's not a Payton Manning, not even close. I think he's taking a huge risk, but if it's true that his family is rich, maybe it makes the choice to hang around another year that much easier.