I think Mumofthree has hit upon one of the connectors to the original post. The rewriting of history classes. This is the age of movies like Hidden Figures. And talking about how white males went around and slaughtered native people and took what they could so Selville could have churches full of silver altars, etc etc. And TV shows, like Brooklyn 99, which has a black Lt in the squad, get stopped and frisked by 2 white patrol officers. The white male is coming off as the bad guy in global exploration and colonization. Though Isabella and Elizabeth 1 were OK with it too. And even the details of how Lincoln decided to take away slavery. It was an economic strike, not about equality. He was losing the war and making slaves free hit the south economically. But that really changes how we look at things. Political expediency is bigger than ever. So teaching these things is risky for those in power.