It's not a little 20 line of code toy project. It's an engaging and accessible writeup of some basic parts of TCP that happens to include some easy-to-understand code.
It's pointless to people who understand how TCP works in depth, but the majority of programmers don't.
It's an engaging and accessible writeup, true. Unfortunately, there are also several glaringly incorrect/misleading points in the article. The fact that it's getting upvoted is just..... strange.
It confuses me that instead of finding these projects uninteresting (as you claim) you took the time and effort to write a reply in a thread just to belittle and dismiss the article.