That's a good point. I did read similar comments to yours in this thread (such as the nearby one by andrewstuart2, and others), before posting about my vi tutorial, and agree with the general argument stated. I've grown from scratch in my own career by the same method you and others describe, i.e. doing a lot of self-study, trying out stuff a lot, poring over tech docs and books a lot (used to buy used ones earlier, when I could not afford too many new ones), borrowing from libraries, etc.

Edit: And have always recommended such an approach to younger developers and aspiring ones, when they ask me for advice, which sometimes happens. Basically tell them to learn as much as you can and invest in your future (with study effort, not only money) for the long term, not just for quick immediate gains.