Quote from RedDuke:
Trading is all about odds. And the odds hugely favor that TTM is just a sales machine.
That being said, I really liked John's book. The funny part, not sure if John himself realizes some of the staff in the book is really valuable, not by itself but with combination with other things.
If successful trader is short term day trader, then any teaching will only distract, so he will not do it. Liquidity could be an issue for short term traders, so sometimes teaching income can be more that trading. That is the only time when someone successful might, just might, consider teaching, but that will require him to abandon trading, and we all know how fast markets change.
Swing or long term successful traders does not have liquidity issue, and would never in the right mind teach, because trading income can easily come close or break 8 figures, and no teaching income can come even close.