the Bears have a philosophy of not employing prominent franchise QBs. There is a pro and con to it, see 49ers with Alex Smith vs. the Giants with Eli Manning but still... the average dude on the street could see that Orton and Grossman were anything but game changers. I'd have grabbed Culpepper, Leftwich or even Pennington if I had a half a chance.
Plus, how do you not retain either Berrian or Muhamed?