I agree that many business books have a good ten to twenty page article trapped inside, with the book length writing required as packaging for sale. Some books, e.g. Innovator's Dilemma, offer a detailed review of examples that help to reinforce the basic concepts (as distinct from a collection of personal anecdotes and reminiscences).
> packaging for sale.
... and for future consulting work, in some cases:-)
Yeah, with the good ones, it's not like the rest of it is just "garbage", and I enjoy reading them, but I think for people who just want to know what the 'big idea' is, you don't need the extras.
That said, many business books tend to suffer from a problem of having a fairly simple concept at heart, and needing to pad that out to make it into something book length. Thus, my site Squeezed Books, which summarizes them. I'd also like to foster discussion of some of the books in question, as I think there is something to be gained from the discussion and dissection of the ideas presented.