It's not just a white thing though? I personally feel it's more of a 'sticking your nose where it doesn't belong' and a superiority complex thing, as in people smugly telling others 'educate yourself'. While I've mostly seen white people do this, I've also seen a lot of liberal POC doing it as well. Everyone wants attention and to feel superior, just some people are using their race as an excuse to invalidate other's opinions or points, regardless of whether they're right or not.