David Greenberg has an excellent essay on bad last chapters of public policy books that I think really puts the finger on the problem here:
But in the end, most authors have themselves to blame. Having immersed themselves in a subject, almost all succumb to the hubristic idea that they can find new and unique ideas for solving intractable problems. They rarely do, and even works that do usher in specific reforms or broad social transformations — from “The Jungle” to “The Feminine Mystique” — do so by raising awareness about an issue, not by providing ready-to-go blueprints.
To put this more formally, the reason “solutions to the problem” generally fall flat is that in most cases the biggest way a book can contribute to solving a problem is simply to initiate awareness that the problem exists. Generally speaking, for either market solutions, communitarian solutions, or regulatory solutions to problems to exist people need to widely acknowledge the existence and significance of the problem. But if people do widely acknowledge the existence and significance of the problem then you’re a good part of the way to the solution right there.