I can understand where this came from even if I don't agree with it.
When the players started taking the knee, Black lives matters was on the players shirts and slogans such as "Defund the Police" and "Kill the Bill" were - rightly or wrongly - associated with the movement and the accompanying riots which haven't helped the cause. I have no doubts a fair portion of the booers are old fashioned, British bulldog, no surrender, racists I think it would have been a better starting point if the message from the beginning was one of equality or some such (I work in IT, slogans aren't my forte). No-one could then go down this marxist route or debate what is trying to be achieved even though I'm sure some would try.
Whilst GS explained very eloquently why the players are doing it - and has convinced me they genuinely want to do it, rather than doing it because they have to which my cynical outlook to life was previously of the belief - the horse has bolted as those against it don't want to listen and have already made up their minds.
Fair points.
Where we are now, though, the players can either carry on with it, or not. If they decide to stop that's fine by me (even though the types to whom you allude will call it their victory). I would prefer they carry on with it, for reasons explained, of course, but I have always and only seen it as a guesture, signifying the existence of a community of equals (like offering a seat to someone who needs it, standing for the National Anthem, and other acts of respect).
As far as those who have made up their minds is concerned, they have either carefully weighed up the landscape but made false inferences, or they are racists. I am not sure that having made up their mind they were ever going to change. My guess is that in the 1970s they would account for 80% of the population. Today it is less. And so it goes; societal attitudes change as the dinosaurs die out and are replaced by younger and different minds.
So I'm not worried about minds made up. I also think there is a place for ostracising those whose attitudes are foolish or odious. Those infuriated by the sight of players taking the knee can stay infuriated as far as I'm concerned, and I hope and expect to see close up camera work on the booers next time England play.
All the best