I disagree. How we change for the better is when people that feel strongly about an issue begin taking meaningful action to change things.
In my opinion, kneeling during the anthem is a punk move, and it's disrespectful of the people who put their lives on the line defending our freedom and enforcing our laws. If the players feel strongly about injustices in this country, maybe they should volunteer some of their time/wealth actually trying to make things better. Or, they can speak out about the issues on their own time, articulating their views. Some have been, but most have not.
I never said players shouldn't be allowed to express their views. I simply believe that they should do so on their own time.
When the players are on the field, wearing a team's uniform, they are employees. If the NFL decides not to do anything about the protests, I can (and have) decided not to support them with my viewership and ticket purchases. Of course, you can (and should) make your own choice.
I'm not sure how you equate the playing of the National Anthem as a military recruitment advertisement, but whatever.