Fair point, but I think your example falls on the other end of the extreme – lacking context. A sufficiently long blog post – or, better yet, a drip campaign from a newsletter over the course of a week or something and narrowly focused on a particular topic – would be able to provide context for why.

Of course, you're putting a bit of money into a book so you might be more willing to follow that advice.

All that said, I have read plenty of self-help books and I enjoy the anecdotes. IF they do help someone written as they are, more power to their authors and may that trend continue.