I've heard about SSC's racism for years, but no one has ever been able to pinpoint anything written that's racist.
Instead it's about a feeling. It has to do with with the general gist of what's written and not written.
If you say you support freedom, the radical left says that's a dogwhistle for racism, since you really mean 'freedom to be racist'.
If you advocate or discuss any problem other than racism, the radical left would say that you're really saying that racism is not the foremost issue in the world, and that's racist.
If you appeal to mostly white men, the radical left says you're racist because you do not have outreach, or you don't represent minority voices.
If you support free speech, you're racist since you're just dogwhistling support for racist speech.
They will never say this of course, but it really has a lot more to do with image than concrete words or actions.
Joe Rogan never did anything racist and has even endorsed Sanders--but he seems* like he could be racist at a glance (muscular, interested in hyper masculine activities, probably drives a pick-up truck) so therefore he is.
I'm willing to consider that there is some racism in the blog, but after years of accusations and no proof, I am skeptical.