What's going on here? CW: racism

There's a video documenting Chinese people being racist towards black people. I have yet to watch it beyond the first few seconds, which is a bad habit because I need to face these things if I'm to be a good comrade. No investigation, no right to speak. The replies contain horrified people of all colors, anecdotes of encountering racism, and right-wingers praising China, admitting unfamiliarity with their game or some shit. My first thought; China's huge. There's going to be racists. On the other hand, I was wondering if there was yet more to this than that.