I'm not sure why you feel the need to bash this person. If you already know the concepts then go read something else. Instead you took the time to write this shitty comment.
This may not provide value to you and thats completely fine. This does however provide a lot of value to the author and to others.
Writing technical thoughts in a way that is simple and understandable is a skill and I think this author did a great job of that.
Also its the internet I can write posts for myself all day long and guess what? Ain't shit you can do about it. I'll keep littering the internet with these "random abrupt posts".