These types of books in general (the whole genre)? 50% b.s./50% basic principles people used to be taught as children but weren't, so adults are having to buy that work in the market. I write and I contract with writers, the market is flooded with books teaching people common sense principles they should've learned at their parents/grandparents knees. Like keeping your word, working hard, not running around gossiping and tearing people down. These books are selling like hotcakes. The problem came about because people threw the baby out with the bathwater. Thinking the previous generations had everything backwards, so a lot of people shunned their upbringing and the lessons (about money, values, relationships, etc.) they were taught from their elders, so now you have a big chunk of adults who don't have a good moral compass or real principles. They're ruled by emotions and a poor sense of self/identity, and they're paying whoever will take their money to get it.
And the b.s. part is just b.s., usually that everything is your fault or that nothing is. Useless.
And the b.s. part is just b.s., usually that everything is your fault or that nothing is. Useless.