Simple? lol we have all seen what happened to Peyton Manning when he didn't have his receivers. And simply put, Jay Cutler isn't Peyton Manning. Look at all the top tier quarterbacks in the league and their receiving core. Each quarterback has a pretty well built supporting cast. Jay Cutler isn't going to help receivers run routes and catch balls. Take your homer glasses off. Cutler is a great quarterback and I will give him the credit he deserves, but you need receivers to put up the numbers he did last year.
P.S. I absolutely love how everyone in this thread is using their brains and not pinning the Broncos losing season on Cutler. However, everyone is all over Aaron Rodgers nuts for "blowing" games because that is the consensus on ESPN. When truth be told, it was the horrid defense.