I agree with most of what you said, but this seems a bit ironic.
Your suggestions almost exclusively involve large investments of time with little established proof that they are efficient. Do you genuinely believe reading RFC 2616 "cover to cover" is an efficient way of solving the specific problems they came across?
I would wager most developers wishing to be "really good" actually have a concrete desire like a greater paycheque or employer in mind. If that is true, I doubt reading someone's booklist necessarily is their fastest pathway, and their economic perspective is exactly what stops them doing so.