alt Hacker NewsIf you want a spoilery TLDR: It's more about the journey. He tracks down the origin, finds the support, finds the support flawed, and leaves you to your own conclusion rather than make a new flawed one.
The basic idea is that the origin assumes a highly critical inner hot loop, don't assume where it is, and optimize there.
There's some other time spent saying this justifies slower abstractions for maintainability elsewhere.
Another point I liked was that there was, apparently, an influential book called Structured Programming, whose content was so universally agreed upon, that all programming became Structured Programming. Nobody needs the book anymore.