I think the players took celebrating too far. So the NFL had to rein them back in. Of course, the NFL can give us all sorts of reasons why they did it but, most likely, it had to do with protecting their sponsors. I forget which player hid a cell phone in the goal post padding and pretended to make a call but that was getting pretty close to on-field product endorsement. If the NFL can't get a cut, they won't have that.