Everyone has freedom of speech. They do not have a right to retain their job after exercising it. The "platform" at game time does not belong to the players; it is the property of the NFL and the teams participating in the game. Just as you don't have a right to a "platform" for your personal, private political viewpoints during a company meeting with customers. And I strongly suggest you go back to history class, because you missed quite a bit if you think Fidel Castro and George Washington are interchangeable.