Why scammy? It's pretty common sense that these books do not offer any recipes for wealth creation, but they do offer something very important: the correct mindset for wealth creation. That is something that many many people lack and need.
Finally, if you find it useless, why do you assume that everybody else does so as well?
> these books do not offer any recipes for wealth creation
Oh but they do: for the authors.
The problem with them is that there is little of substance and lots of feel-good hand waving. The good bits could usually be summed up on a page. Compare and contrast, with, say "Founders at Work" where each story is different, unique and interesting in its own way.
Before you dismiss Tim Ferris out of hand for his background, you should consider dismissing him on the merits of his methods of holding your breath longer than Houdini or eating ginger and sauerkraut to gain muscle.
Finally, if you find it useless, why do you assume that everybody else does so as well?