I think people coming from most other languages that have objects get very confused about prototypal inheritance. The significance of first-class functions is also not obvious to people who don't come from a functional programming background.
I think you're right insofar as it's easy to "get going" with JS and see things happen in a web page. But if you're looking to actually learn how to build non-trivial apps, a solid grounding in the language is pretty key.
I think one beginner and one advanced book maybe. True, I did come from a different background than most (having learned both those features in other languages before ever doing javascript), but do you really need 7 more books to tell you about it?
I think the post is bordering on book affiliate spam.
I don't disagree with you on that point. Two books should be plenty. I'm only pointing out that there's a lot of utility in learning about JS as a programming language, completely divorced from DOM stuff.
I think you're right insofar as it's easy to "get going" with JS and see things happen in a web page. But if you're looking to actually learn how to build non-trivial apps, a solid grounding in the language is pretty key.