The NFL bears about the same resemblance to “Football” as “professional” wrestling bears to collegiate wrestling. (Which is about the same as collegiate wrestling bears to warfare, or an actual fight)
Which is to say, almost none whatsoever.
The NFL is a form of entertainment. Bread and Circuses. The entertainers Are free to do whatever they think will further their entertainment value.
The people who pay to watch their antics are free to decide that they aren't entertained and turn their attention (and their consumer dollars) to other forms of entertainment.
In short? Of course the NFL has a “Right” to pull a “Charlie Sheen”
and it's audience will go watch NASCAR....