He's making low value content/the culture of the company is horrible/he's a fraud/it's more luck than skill. The actual critiques are personalized to the content and, to one extent or another, valid, but the social purpose of the critiques is universal which is that I felt uncomfortable that reading this might mean I have to re-evaluate my worldview and I'm going to dive into the comment section and upvote all the people telling me actually, I don't have to do that.
I actually spent over an hour writing 750+ words of my takeaways reading this document and shared it privately with a few founder friends of mine and I briefly considered also posting to share with the community but I took a look at the comments and took a look at what I wrote and decided I didn't have the energy to face the endless onslaught of nitpicks and misunderstandings that are driven, at the end of the day, not by a genuine intellectual desire to reach an understanding, but by the need to prove emotionally that others are not taking this seriously so I don't have to either.
All I can do is be vague and say I think this was an enormously valuable piece of writing that is worth engaging seriously for what it is as it might change your worldview in several important ways.
But also my larger meta-point is that there's a now near ubiquitous "sour grapes" attitude that's pervaded HN that makes it an extremely unpleasant place to hold a conversation and people reading should be aware of this systematic bias when reading comments here.
I try and remember to not HN at the weekend, obviously forget sometimes. I tend to find sticking to Ask HN is better at the weekend.