This is literally what software licenses are - do you think GPL etc. are fool's errands too?

This isn't software, it's a blog article. Different things are different.

Can you imagine a book with a page in the front that says "you may use text for graduate course study at an accredited university, but not for undergraduate study or autodidactic reading?" People would read it (maybe) then then go "huh that's weird" and continue doing whatever they were going to do with it. It's the same with this article.