In a word, No.
Star athletes have outsized egos and outsized abilities. They're used to getting their way because their talent causes owners, coaches, and fans to excuse things that other people would be sat upon for. There are any number of disruptive persons who can't get along with teammates, but who remain on the team and on the field because their performance means that the cost to the team of having them is less than the benefit to the team of having them. Likewise, there are not a few professional athletes who have had scandals and brushes with the law -- DUIs, domestic violence charges, assault, even rape accusations -- who nevertheless play through the drama. Why? Because their value to the team outweighs the negative publicity the team endures as a result of their playing for them. When Deion Sanders was playing for both the Dallas Cowboys and the Cincinnati Reds -- something he would never have been allowed to do if he wasn't bringing benefit to both teams -- he decided he didn't like the Reds' team uniform. It didn't fit his personal style. So he cut the sleeves off his jersey. Rather than make him wear what everyone else was wearing, the Reds had all their players cut their sleeves off to match this sometime outfielder's personal style.
So, when an athlete mouths off on some political issue, the team and the front office put up with it. Up to a point. When you stir up a bigger hornet's nest than your play is worth, then suddenly you wind up benched. Maybe eventually traded or out of a job. It's simply a matter of costs vs. benefits. Are you worth the turmoil, the loss of fan base, the distractions in the locker room?
Colin Kaepernick would be playing today, whatever he did, if his numbers had stayed up where they needed to be. But he hit a slump, or failed of his promise, or something. He lost his mojo, lost his starting position, and was on his way to the dreaded status of "journeyman quarterback" -- every team's backup. And he didn't like it. His solution was to kick up a ruckus, to force his team to acknowledge his value. One way you know you're still king of the hill is to do something that forces everybody else to cover your anatomy for. But Colin's numbers weren't all that great. He simply wasn't worth it to keep on the team -- any team. He became unemployable. As they said in The Godfather, "It's just business."
Meanwhile, Kaepernick's stunt has ignited a lot of furor among fans and a stubborn response among many other players. A number of NFL players are now refusing to stand for the anthem, or otherwise making a show of their political views. So we'll know they're not putting up with racism, or something. They're still employed because they're still cranking out the performance the team needs. Of course, some of those teams are hopelessly inept, and the players aren't disciplined, not because they're star athletes, but because the whole team is ill-led and under-powered and a general mess. You'll see little of this stuff on well-led teams who are contending for the playoffs. And if you do, at the center of it will be someone too good to be let go.
Until he isn't, anymore.