@Octavian responded to me which explains my view nicely.
A racist tweet is still deplorable, but it's being highlighted now firstly because he's at the peak of his 'fame' but also to discredit him as a person and his claims that YCCC is institutionally racist.
I'm of the view that no one is whiter than white (probably not the best expression on this topic). We've all done things we aren't proud of. There's a difference between an indirect tweet compared with years of direct confrontational racism.