No one said every flaw, just the mega bad ones. Say maybe my friend has a drinking problem, or some other shit like that, thats something you can work with them on. Being a racist piece of shit is not like that.
Also similar to what pocketchads said, would it be different for you if say you had a black spouse and your dad wanted to genocide blacks? As others have said its more likely you just don’t care because it doesn’t affect you, as opposed to this just being some overriding principle that you are fine with it as long as they are good people.
People do a lot of different awful things, racism is but one. Alcoholism is a good example. Unless a racist is in a position of power, alcoholism is probably going to do more harm. Racism is an important character flaw, but it’s hardly the worst one.
Expecting someone to cut a racist out of their life requires more courage and selflessness than most people have. Instead, most people just do what they want and work backward to justify it.
Also clearly how much they are willing to work on their issues matters, if they do or say something racist, get called on it, apologize and pledge to do better, and seem to be, thats one thing. Same with the drinking.
When you say hey man thats racist and they say lol no it isnt, stupid lib, fuck you, then well, fuck them.