[lkjhdcba]

I believe it was a twitter thread that he unrolled and mashed up into a medium post. On twitter he's often abrasive and kind of a dick as a character, and the tone carried into this post. He's doubled down about it because his rant seemed to have angered a lot of people among his demographic following, so if you follow him you'll probably find more explanation.

>this piece was meant for math PhDs

Lol it is absolutely not meant for math PhDs. I think anyone with a bachelor degree could follow the math (probably, I don't know much about the university system works in the US).