3 things are killing the NFL.
1)Salary Cap
No more dynasties. Talent is diluted. Very little fan/player connections being developed.
The bad teams are just as bad as before. The good teams are not as good as before.
2) Saturation
Used to be Sunday and MNF. It was appointment television. Now, who cares? There are games seemingly every other night. And, it is usually bad football. I'd rather watch Big Bang Theory re-runs.
3) Political Correctness
This is killing America, not just the NFL, but that is a another story. The NFL used to have zero tolerance for PC bullcarp. Now, they have zero tolerance for any dissension to their PC bullcarp.
When you dance with the Devil. You don't change the Devil. The Devil changes you.