OK, so they are pulling our leg, ok, so they aren't really serious, or scientific. Nonetheless, Komar and Melamid demonstrate most convincingly and amusingly why design should not be done by focus groups. The book is a hell of a lot of fun, besides raising profound questions about the meaning of art.
Actually, you could take their argument one step further and say that this book undermines the very concept of user-centered, iterative design. Want design that works for everyone? Follow user-centered design methods – follow Komar and Melamid's methods. The result is sensible, dull, pedestrian, and uninspired. Great design comes from breaking the rules, from not listening to the averaged voice of the average citizen. In the Chapter 3 of Emotional Design, I use their results to argue that maybe dictatorship in design is a good thing. I'm writing an essay on this topic and will hyperlink it when I get it done. Meanwhile, read Henry Lieberman's wonderful essay on the topic: Lieberman, H. (2003). The Tyranny of Evaluation.