The anger for kneeling by conservatives or the anger by the players to respond by kneeling?
There is a time and place to protest, my opinion is that it's not during the national anthem, but, that is their right so who am I to say they can't? I simply don't agree with it, but I won't hold it against them for protesting a cause. I do not think, for example, is in the case of the US men's NT, is to take an official stance to it. If some want to, fine, if the team wants to, fine but don't take sides as an organization.
I ask initially, because I'm not sure what you're referring to. Kapernick for example, you could argue was "canceled" but he has been given other opportunities, to re-try out but if I recall his demands were a bit diva like. Don't quote me on that because I honestly can't remember so shooting from memory here, referring to a try out he did at a high school or something like that.
Per the players in the NFL...these guys make millions upon millions to play a game and paid by a large section of the population they claim alienates and systematically oppresses them. If they really wanted to implement change that impacts their population I would think they'd take their millions and live in the rough communities they came out of and reinvest to help youth in those areas. That's my take. Granted, I know a lot of these mega-athletes do donate millions already or set up really good charities which is awesome. But at the same time, there is a lot more they could do with that money if they really wanted to make a difference but its nice to see many of them at least giving it an effort to give back.
Conservatives that are pissed off about the kneeling need to deal with it, its one thing to not like the form/timing of the protest, but to outright say they can't do it is wrong. Kneeling for the anthem is a peaceful protest 100% their right as per the Constitution. If people really don't like it, they will tune it out/change the channel/or stop paying for tickets.
The cancel culture does more harm than good and that goes for both sides.