In the 1950s, black people were barred by law from buying homes in the best neighborhoods. They legally and systemically were boxed out of one of the biggest wealth booms of the middle class ever.
Also, once upon a time you could legally own black people. Jim Crow laws, voter suppression, etc. This isn't stuff from 500 years ago. There are people alive today whose grandparents were slaves.
So systemic racism does exist. And smart liberals care a lot more about that than what race of hooker gets your dick hard. But that's why some black person hating whitey matters less than when white people are racist.
I do think the discussion of racism often ignores class. I would rather be born to a black lawyer than a white coal miner in 2019. I'm a big fan of equality of access, not outcome, which makes me a somewhat moderate liberal.
By all means call out racism against white people as you see it. I've read some articles in the black blogosphere that made me cringe, although some of them likely were meant for humor. It's ok to take offense. I care way more about how police make traffic stops than racist jokes, although it is all part of the same system.