In a post titled "GIGO" (for those who don't like acronyms, Garbage In, Garbage Out), Andrew Gelman wrote this gem:
as long as the “garbage out” gets media attention, there will always be somebody willing to supply the “garbage in.”
The general drift of that post, and the previous one that led me to it, is a critique of the management consulting industry. Having worked in that industry earlier in my career, plus having studied at the school at which Michael Porter is a famous dude, I am familiar with how this industry works.
We even had a term called "blank sliding." This is exactly what you think it means... consultants are trained to write a "draft" of a client presentation consisting of all blank slides that only have headers written on them. Headers taken together tell the story of the presentation. Eventually, the slides are filled in with content. In a nutshell, the story is created before the meat is ready.
While this sounds horrible, it is not really that bad, if used properly. It creates a culture of getting the story right and focusing a lot of attention on the story. If the analyst uses this method directionally, allowing rewriting of headers, or maybe even the whole story, as the contents are filled in, it could lead to a good product. Frequently, however, it creates the situation described by the Gelman quote.
PS. Andrew is probably right about Michael Porter being paid big bucks. He is one of the most expensive public speakers (link).