Maybe I'm being unnecessarily harsh here, but this seems to have about the same level of substance as a low-level JS tutorial you'd find on Nettuts or something.
The code may be something you could find on Nettuts but I think the point is to challenge the belief that we should all "just use jQuery". Not to show you how, but rather to explain why.
"How's" are easily Googleable, "why's" are a little harder and therefore more valuable, IMO.
