Rule #1 for salesmen is, never resent your customers. This applies to any business enterprise which sells a product or service. With respect to personal interaction, people actually do broadcast the essence of their inner feelings. It is easy to fall into the trap of resenting someone who has more than you do or one who appears to have an easier. Resentment is a huge sales killer.
By resenting their audience, NFL players are destroying their livelihood just to make a social statement and vent their feeling. Is the resentment justified? That is one question. Another is, is it worth it? Everyone has to make their own deals in life. Resent the people who pay you and let them know it? You are the one who is going to take the loss.
Football is highly vulnerable to this resentment principle. People watch football as an escape mechanism. Part of what people are escaping is being constantly preached to.
The last piece of advice I have for NFL players is to make sure you know what you are talking about. Otherwise you will shorten your careers fools out of yourselves at the same time.