I used to have that mindset and it felt like a strength at the time, but now I see it as something that held me back from being better. Obviously it's best to stick to a high quality subset of the language in your code. But the brain doesn't run out of storage space, and having a deeper knowledge of the whole language brings context and confidence that makes you better at developing. These books have a refreshing, academic willingness to deep-dive into obscure language quirks out of pure curiosity, and the result is a fascination with the language and an understanding of why things are how they are. This means my whole approach to writing JS is now positive and creative, not resistant and resentful. Honestly, buy all of these books and read them, they're short and manageable and geeky and fascinating.
I felt that way when I was younger but eventually lost my taste for poring over masses of "just-because" detail, and became more sensitive to the cognitive cost of doing so. It isn't merely that the time and energy could be spent on other things, but that the brain responds to learning by patterning on it. If I spend energy on that, my work gets more like that and my brain thinks more like that, and I don't want them to.
(By the way, I'm not criticizing those books at all. I don't know them, but if they're as good as you say I think that's great.)
