There is a fairly consistent distinction to be made between, say, Martin Luther King’s actions, or Rosa Park’s actions, on the one hand, and the NFL player actions on the other. There’s a consistent way to approve of the former while disapproving of the latter.
I don’t know what others call it, but I think of it as the Victor’s Distinction.
That is, you can approve of Parks and King, because they won. Their civil rights struggle is safely in the past, and society has agreed that what they did was great and that they were heroes. Today if you blame Parks or King, you experience some serious social pushback. So if you adopt the Victor’s Distinction, you approve of what they did.
Colin Kaepernick? He hasn’t won yet. Black Lives Matter? The people who take down statues? They’re in the middle of their struggle, and you can condemn them without universal social pushback. So the Victor’s Distinction doesn’t require you to approve of them: you can criticize them all you like.
It’s convenient and consistent. Fifty years ago, those who adopted the Victor’s Distinction could approve of Harriet Tubman while disapproving of MLK, pointing out how he stirred up trouble in otherwise peaceful communities. A hundred and fifty years ago, those who adopted the Victor’s Distinction could approve of the Boston Tea Party while condemning Harriet Tubman for violating property rights–I mean, sure, maybe slavery should end some day, but stealing people from plantations wasn’t helping the cause at all. And in 1773 I’m certain there were people who approved of Pilgrims who left the land they were bonded to, but wagged their fingers at the hooligans throwing perfectly good tea into the Boston Harbor.