I can understand it to some extent. Here's someone, who claims he is a behavioral expert and scientist, and who offers a seemingly plausible simple method to understand yourself and other people, and how to use that method to efficiently interact and work with others. Who wouldn't want that?
Unfortunately the books are still sold. I've considered printing stickers that warns about the nonsense and sneak it on to copies in book stores. How else can we stop the proliferation of this junk?