From other comments it looks like the author can be quite vitriolic, so it is possible that a lot of the criticism he receives here is fair in tone. But to me this looks a bit premature, the article sounded like a declaration of intent (especially regarding refactoring the code per se).
In particular I understand that there are wrong ways to complain (and possibly the author is guilty of them), but this specific blog felt over the top and emotional (something I sympathize after unrelated experiences in failing to understand how to organize an Poly/ML project) but not unfair.
That is what this post is advocating for, his own fork of black.