In a recent interview, Don Norman warns of the perils of design by committee:

You don't do good software design by committee. You do it best by having a dictator. From the user's point of view, you must have a coherent design philosophy, and I don't see how that could come about from open source software. The person who's done it best is Steve Jobs, and he's well-known for being a tyrant.

Nowhere are those perils illustrated better than in this cautionary tale from General Motors:

In the mid-1990s, then-General Motors Corp. Chairman John G. Smale decided to bring the world's biggest automaker a dose of the give-the-people-what-they-want ethic that had animated Smale's old company, Procter & Gamble Co. And what the people wanted was sexy, edgy and a bit off-key; in short, a head-turner. General Motors' culture took over from there. Design would be by committee, the focus groups extensive. And production would have to stick to a tight budget, with all that sex appeal packed onto an existing minivan platform. The result rolled off the assembly line in 2000: the Pontiac Aztek, considered by many to be one of the ugliest cars produced in decades and a flop from Day One.

What's worse, the Aztek was actually a good idea at the right time. It was killed by poor execution:

The Aztek represented all that is wrong with GM's design process, that official said. The concept car actually did something few GM designs do: arrive before a trend -- this time, the crossover SUV that combines the attributes of a truck and a passenger car. And GM had high hopes to sell 50,000 to 70,000 Azteks a year, establishing Pontiac on the cutting edge.

Then came production, the executive said. The penny-pinchers demanded that costs be kept low by putting the concept car on an existing minivan platform. That destroyed the original proportions and produced the vehicle's bizarre, pushed-up back end. But the designers kept telling themselves it was good enough. "By the time it was done, it came out as this horrible, least-common-denominator vehicle where everyone said, 'How could you put that on the road?'" the official said.

Sales never reached the 30,000 level needed to make money on the Aztek, so it abruptly went out of production last year. The tongue-in-cheek hosts of National Public Radio's "Car Talk" named it the ugliest car of 2005. "It looks the way Montezuma's revenge feels," one listener quipped.

The Pontiac Aztek is such an egregious case of compromised design that it is referenced multiple times in Steve McConnell's Code Complete 2:

Maybe you think the Pontiac Aztek was the greatest car ever made, belong to the Flat Earth Society, and make a pilgrimage to the alien landing site at Roswell, New Mexico, every four years. If you do, go ahead and believe that requirements won't change on your projects. (p.40)

If we didn't know about geometric shapes like circles, squares, and triangles, for example, we might come up with more unusual shapes like squash shape, rutabaga shape, and Pontiac Aztek shape. (p.152)

This technique is useful about as often as you find someone who would rather have a used Pontiac Aztek than a new Corvette. (p. 365)

I was intrigued by the number of times the Aztek was referenced in the book-- three times is not a coincidence. And at least one international reader was a little miffed since he had no idea what the Pontiac Aztek was:

Another thing I didn't appreciate is the use of a few American comparisons and references. I presume the book is written for an international audience, in which case such culture-specific idioms should be avoided. The Pontiac Aztek is featured quite prominently (never having seen one, nor being aware of its reputation, I have no idea whether the choice for that particular car has any meaning, be it positive or negative). I also remember at least one reference to some sports terminology which is obsure to most non-Americans, probably baseball-related. [..] Only four stars due to the superficial discussion of some interesting topics and the Pontiac Aztek references.

The Aztek is uniquely American. And too often, so is the least common denominator result of design by committee.