How could an author who knows nothing about you possibly be better than yourself at construing an example applicable to you?
It then seems to me these kinds of books must be made for people who want others to think for them.
So maybe all these books should say is: "Think. Your problem is a lack of aforementioned activity. If you need some food for thought here's a list of ten pithy principles. Flip to page two for an afterword by my publisher."
Of course that wouldn't be good business sense. Why show someone the spring when you can sell them water?