I'm a real veteran, since you brought it up.
First of all, this issue has nothing to do with the Constitution. Anyone who has read the Constitution knows that.
Is kneeling during the National Anthem disrespectful? Yes. Do I think it should be banned? No. I see disrespectful acts every day, by people of all colors and ethnicity. Lot's of people disrespect the Country, disrespect their parents, disrespect authority of any type, disrespect each other, and worst of all............disrespect themselves. We'd be mightily challenged to ban all disrespect. I also don't think any of it should be glorified, but I accept that others do.
Do police officers illegally target people of color? Yes. Do police officers have biases and prejudices? Yes. Are the majority of police officers racists? No. Should people of color share some of the fault for this attitude? I think so.
In the year 2020, is racism a result of what happened 150, 300 or 400 years ago? Maybe for a small segment who's grandparents never got over the Civil War. Racism isn't about skin color. Heck, most white people I know wish their skin was darker. Racism is about differences in culture, behavior, and most importantly attitude. "They're different, so I don't like them". Racism comes in all flavors, anyone who thinks only white people are racists, hasn't been around anyone else.
My son has racist beliefs. He didn't get them from me or his mother or any of his grandparents or the history of slavery. He formed his attitudes with 46 years of living beside, working with, socializing and befriending people of many races. I disagree with many of his perceptions, but they are his.
So, if players kneel during the National Anthem on game day, I won't see them because I don't watch pre-game, half-time, or post-game drivel. I wouldn't care if I did see them. But, if the NFL gives a washed up has been of an ex-quarterback a job just to be politically correct, I'll stop watching them.