Primarily the decision of the commissioner of the NFL made this decision based on the ratings drop that the NFL has gotten in the past two years. As I understand it the ratings have dropped by 10%.
When the ratings drop the advertisers would want to pay less for their ads as they are no longer reaching the agreed up on viewers.
Also the cost a radio and TV corporation is willing to pay to transmit your product over the air is reduced based on the fact that there are fewer viewers.
As I understand it the NFL revenue is around a billion dollars or so. With a 10% decrease in viewership, this is a large amount of revenue to lose, in advertisement cost and the amount you are paid by the media outlets in showing your product, because the players want to make a political statement.
As it is they have lost some viewer for a lifetime. These viewers are no longer interested in viewing the NFL product.
The commissioner also see that this is a distraction,because even though the players have indicated their protest against the flag and national anthem has nothing to do with the veterans of the United States military as well as those on active duty. It is difficult to separate the two.The military veteran fight for the flag. Now you want to make a statement that you are disrespecting the very piece of cloth they are and has fought for.
I know as a United States military combat veteran I feel disrespected when people disrespect the flag and and national anthem by not standing for the playing of the national anthem and raising of the flag .
So this is a public relations situation the commissioner is trying to address, also.
I have not watched a NFL game for 2 years.At present I still might not watch another NFL game. I have found new things to do with my spare time I formerly devoted to watching a NFL game on TV.
I hope this has been of some benefit to you, good luck.