I agree. But note that I was careful to say:

this article is really just telling the LW crowd things it already knows, and, more importantly, already appreciates beyond merely "knowing it in the abstract".

I'm fine with articles that tell us stuff we already know, or that someone wrote an article about before. No one's perfect, we need remindings, the article might present it with a better perspective or explanation, etc. What makes this article different is that LWers don't just know it, they actually appreciate the insight, i.e. put it into practice and successfully avoid errors based on assuming something has infinite value.

And, for that matter, I don't think that any of the newbies, except maybe the really "out-there ones", have made such an error.