Having previously had my say on this, I can't be arsed typing it all again...
I think we're straying into absolutism again here - agree with taking the knee = good, disagree with taking the knee = bad.
It's really not that simple. When Colin Kaepernick took the knee it was a powerful individual gesture. When other American sports men and women followed suit it was also a deeply symbolic display and I loved seeing it.
Somehow along the way, that gesture has been co-opted by Black Lives Matter and at this point is irrevocably linked to them.
To make my position absolutely clear on this, I'm not a part of the "all lives matter" brigade. I get the distinction and I agree that black lives matter (the principle). I'm just deeply uncomfortable with Black Lives Matter (the organisation). Their stated aims go way beyond their remit and by adopting their salute of sorts, whether they mean to or not, footballers are implicitly signalling their support for that organisation. At the risk of invoking Godwin's Law, it's a bit like a German player doing a Nazi salute as a goal celebration and then saying "Well, it was a tribute to my grandfather who fought in the war, it's nothing to do with the Nazis" - it wouldn't wash because that gesture is intrinsically and inseparably linked. That's probably a bit of a crass metaphor, but like it or not, adopting a gesture linked to a particular organisation suggests support for that organisation.
If football was to come up with its own gesture to symbolise racial equality, be it an arms folded stance or hopping up and down on one leg for all I care, I'd happily applaud it whenever it was taken. I won't applaud a gesture that glorifies a Marxist organisation that wants to see the police defunded, capitalism deconstructed, drugs decriminalised (along with all drugs-based convictions quashed) and, in the past at least, has advocated getting rid of the concept of the nuclear family.
That said, I wouldn't boo it either because booing is a blunt instrument that sends the wrong signals and plays into the hands of those who are happy to dismiss any dissenting voices as racists.
That's why people get irritated when virtue signallers like Rio Ferdinand and Gary Lineker make pronouncements from their high horses about people "getting educated" because that cuts both ways! I don't doubt that footballers are taking the knee with honest and admirable intentions, I do doubt that many of them realise the full extent of the message that gesture gives.