The only way these things will stop is when people vote with their feet/wallets. If people stop showing up to ballgames and watching the games because the players are disrespectful, it will stop by itself and mediocre players like Kaepernick will get fired, but as long as he fills seats, keeps the NFL in the news and on the TV, he's going to stay.
The same thing happened with the third wave feminist movement, it's still there, but it's contained because every local organization that got infected with it has largely failed.
People by and large stopped supporting terrorist organizations like BLM because their methods and message have been proven to be faulty. It's slow, but it's happening.
Anyone remember Occupy or anti-nuclear movements or hell, Greenpeace and PETA? Yeah, no leadership, no message, faulty reasoning, failure. They're still there, but nobody takes them serious.