I'm only pointing out there that kneeling is not a sign of disrespect. In fact in most cultures (including ours) it is actually a gesture of respect and reverence... and that's not my definition you're going against, that's THE definition. If you find it disrespectful that's fine, but that's strictly your interpretation of an act that in every other use is respectful at best and neutral at worst. 

The reason that's a problem is that you seem to be muddling up the act of kneeling during the anthem with the reasons why they're doing it. You (and obviously many others) have decided that this protest means what YOU want it to mean (disrespect the flag, disrespect of veterans, etc) rather than what it means to them. You are of course free to decide what you think of these players and their teams. But as far as how you should react, I'd humbly suggest you react like an American, and support their right to protest even if you don't agree with them, and then enjoy the rest of the game.