I don’t see how grammar is racist.
It's not that grammar is racist. It's you who are racist if you don't make mistakes!
A few more quotes from the website bjorn quoted above. I'd put them in the category: "Where Orwell failed with his imagination."
"Professor says grading, good grammar are examples of white supremacy"
“grading is a great way to protect the white property of literacy in schools and maintain the white supremacist status quo without ever being white supremacist or mentioning race.”
"Faculty workshops designed to persuade teachers not to grade based upon merit are popping up at universities..."
this workshop is ... designed to teach faculty “how to assess writing without judging its quality.”