touchdown celebrations

After scoring a touchdown against the Carolina Panthers Sunday, Chicago Bears running back Marion Barber tried to perform a celebratory backflip. Bad idea, as he was only able to complete three quarters of the acrobatic move, and fell flat on his face.

From T.O's infamous "magic marker celebration", to Deion Sander's dancing after a score , celebrating a touchdown in the NFL used to be entertaining. So why did the NFL take the "fun" out of scoring?