I completely agree with the owners not signing him, he's not a top 30 QB in the league anymore. He should have the right to say these things/protest racism in America. He should also respect the owners rights not to want him on their team. You cant have it both ways.
My thoughts on him kneeling. When someone starts a movement, like what Cap is trying to do, there will always be push back and public outcry, if there isn't that means you're not really having any effect at all. If what he and the other NFL players are doing can lead to conversations about this at a national level and policy reform then it is all worth it in my opinion.