Because they paid for it.
It’s possible you have information that I don’t, but so far you’ve been holding out if you do. I will concede if you provide something persuasive.
Otherwise, well, can we really consider all the references to “Amateur golfer” or “Novice” throughout the book as merely incidental?
His 5 lessons pivot action was explained in the most popular Ben Hogan video on the internet, the instructional bit he did after the shell match where he’s clearly addressing novice golfers. Initiate the downswing with the lower body; something amateurs are notoriously bad at. It’s meant to put the golfer in a position to hit the ball from the inside instead of spinning out with the upper body. You may not agree with how he teaches it and that’s fine. I personally think he could have done a better job at explaining in some parts.
The 5 lessons grip is not a weak grip. If done properly there are 2 to 3 knuckles showing (thumb not directly on top of shaft), and the grip pressure he recommends promotes the club head turning over through impact (pressure in the three last fingers of the left hand). There’s nothing hook proof about anything in this book.
Come on man help me out here!