I don't like to get too involved with these Sam threads because the points raised by his detractors tend to be too overly simplistic to me. When the Rams went up against Dallas and San Fran in a murderous 5-day swing last season, they were running DRich ineffectively into the middle of the OL looking for usually non-existent holes. Dlines as good as the Cowboys and the '9ers could simply ignore the run and concentrate on stopping the Rams' biggest threat, an accurate Sam Bradford. If Zac was ready to roll then and was given his shot, does anyone think Dallas or 'Friscoe would have been dominant, that they may even have lost to our Horns? An effective Zac would have forced the opponents to crowd the LOS, allowing more open space for Sam's flyguys. If the D dropped more people into coverage to stop Sam, Zac would have killed them.
If you are going to criticize a player, especially the most critical position, then take the entire circumstances he was under into consideration. Quite frankly, I have never seen a big name QB ever having to start his pro ball career the way Sam has.