"The thing about working on yourself is that it’s actually work. Reading an article, or a book on behaviour, self-improvement and what else doesn’t actually change you any more than reading Harry Potter does."

This is well put, and I think part of the reason so much self-improvement material is drivel. Generally, I've noticed that some of the most pathological people are the most into 'self-improvement' as an idea. That being said, their brand of 'self-improvement' generally does not extend beyond reading and quoting books by various gurus.

On the flip-side, those I've met who are actually highly motivated and disciplined, have never picked up one of those guru books.

Reading up on something is one thing, and in many cases, it's an important first step. There's no way to start using a new language without reading something. That being said, simply reading is not enough. On top of that, what you read has to be actionable. The self-improvement platitudes are not actionable. Reading a book on Python does not turn you into a python developer. Why should reading a guru book turn you into one?