I don't know, I went to a community college. I don't know what grades other people got on their essays, but sometimes we did peer revisions and I saw the quality of other people's writing. They called me racist and elitist if I made too many grammar corrections, so I can only imagine what they said about the professor when they get a bad grade because I stopped correcting their grammar during proofreading.
There's also this thing that sometimes happens where the professor adjusts for privilege in grading. The effect is that I would get a B+ or an A- for having a couple typos, but someone who can barely spell or formulate a complete sentence might get the same grade as me or even better.
And if I get an A in the class or on a test I have to keep it a secret or all my classmates will hate me and claim it was because of white supremacy or some shit.