It’s not aimed at introductory programmers. It’s aimed at more experienced programmers to suggest to them that they can show new programmers what’s possible.
People don't need to explicitly audience-tag every single thing they write. I don't know if "entitled" is the right word, but it's really an annoying demand. Most times, if you can understand something, or are willing to Google the jargon, then you're part of the audience, and that's plenty of precision.
I can Google medical terms until I pass out, but that doesn't make me the intended audience for a medical research paper.
Besides, I'm not suggesting (or "demanding") that all articles explicitly state their target audience. Just that this one does a poor job of indicating it.
So I think it's a poor argument when the parent comment (to which I was responding) assumes an exclusive target audience: "not introductory programmers... more experienced programmers".
You could argue that one was supposed to assume that from context. However, I didn't make that assumption whilst reading, so I especially wouldn't expect "introductory programmers" to pick up on that either.
You can probably understand most medical research papers after reading a few dozen medical Wikipedia articles and taking an introductory stats class. Math and physics research is a little more difficult.
What part of "I think some of us who have been doing this a while have been doing a terrible job of showing what's possible to those folks who are somewhat newer." didn't you understand?