Well, I don't see much difference in one charging for a book they wrote or charging for educational videos and/or training they designed. I have definitely found some shady 'teachers' in this industry, but I have also seen some really good ones.
Teaching is a obvious route for those who are capable of teaching. Trading is hard work, takes time and effort, whereas teaching someone your 20+ years of experience, can be a bit less time consuming and extremely rewarding, assuming there is at least a thousand students or so.
As long as the teacher is transparent enough, doesn't claim to win 100% or 90% of the time,etc,... than maybe they are offering something in honesty , because they know it is valuable.
Thank you for the book titles, I will definitely check them out .
Everything in the market is like a fart, if you have to force it, it is probably shit