It all depends on your ambition. As for all human activities, a small minority is interested in a serious pursuit with a majority wanting quick easy methods, answers and solutions.
If my ambition is mainly to not continuously look in the woods or lose my ball in any lake not being able to carry 150 yds I don't think I want to spent too much effort or money. I would be happy with a simple method allowing me to not lose face and enjoy the game with colleagues or friends.
Jim Mclean identifies the arms swing as an easier beginner's swing and the body swing as that for a more serious golfer. It would make life easier if the various teachers clearly identified if they are geared, as Bertholy, towards excellence or teach the easiest way possible to get a reasonable golf swing.
However there is also the argument that if you want to teach at high level also requires the instructor to be of high caliber. Easier to pretend that golf is not complicated, that you have discovered one two or more simple magic moves and that you can guarantee success in 30 says or money back.
