It is funny on the attitude of an Olympic athlete differs from an NFL player. Nothing makes they Olympic athlete more proud than to stand and salute THEIR flag while THEIR national anthem plays, while an NFL player, who is probably making a lot more money than the Olympic athlete ever will, uses that time for a protest.
If a celebrity or a professional athlete wants to make change, then there is a lot they can do other than disrupt an act that a majority of people hold sacred. They could call a press conference, set up a charity, run for office, or any of a number of other acts. In this age of Twitter and YouTube it is notoriously easy to for a notable person to draw attention to an issue and raise funds to help make change. A lot can be done, but it seems that people care more for the disruption than whatever issue might be seen.
Also, how can the NFL brag about their product creating unity while at the same time they are creating just as much division. What are the stats for the chances of a person getting into a fight because they have 49ers gear in Oakland verses the color of their skin. Or a person in NYC getting verbally assaulted because they have a Red Sox hat rather than their sexual orientation.