I agree, it is surprising, really, that as a culture we prize the biggest/most expensive/exclusive yada yada things : )
You see it with cars, houses and clothes, plastic surgery and dental care.
On computers there is a fair amount of interest in mice and monitors, but for some reason the keyboard gets short shrift.
Nah Americans seem to get the biggest stuff
So if you think keyboards then it would have to be the biggest keyboard therefore full size.
If you take that analogy further, Americans of old did not care for smaller more versatile cars before, e.g. honda civic, ford focus, which if you think about it are more better driving cars than their heavier bigger saloon bigger brothers e.g. accord, mondeo. These cars have more "features" but do not get the basics driving as good as the smaller cars. This goes with keyboards where the more "keys" the better, without a second thought about how good each key feels beneath the finger. So you start to see these keyboards grow multimedia and macro keys which are convenient but are not necessary to typing experience.
Basically a largish proportion(over 50%) of Americans do not value quality goods, otherwise people would be spend much less money on Chinese goods. And this is not just an American idealism anymore, the rest of the world has this problem. Niches are no longer filled they are ignored or worked around.
The problem is people have become too reliant on numbers, you see this everywhere, where numbers are used to provide a tangible or physical means of being measured. E.g. car size, engine size, camera megapixels, keyboard keys, screen size, cpu speed, etc
They make it easier to compare different products and services, but they do not allow people to compare intangible feelings like, feel (using a keyboard), work flow (no number pad so i can move my hand from the keyboard to the mouse faster), experience (hearing keys so i can respond quicker to typing and type faster by not bottoming out my keyboard), robustness (feels like a tank, therefore i believe it should last like a tank, no need for warranty with these sorts of things)
This is the type of intangible qualities people are beginning to ignore because it cannot be translated into words as easily and reviewers put much more emphasis on stuff they can compare and not on what they believe to be unimportant and not worth the cost. Look at the many reviews who look at DAS keyboards and the hhkb pro2 look at their shocked expressions at the price of the keyboard, they often think the cost of the board is to do with the blank keys (which actually are more likely to reduce the cost rather than increase it) as they believe it is a keyboard used to help people to touch type. But actually the cost is for the special key switches which they do not value, and say "it has a nice action" and leave a one line comment.
With people relying on reviews more than ever before the whole world will start to lose quality products because they are not understood. The only products today where intangibles are more stronger than ever are in fashion, but then girls are always more in tune with their intangible side than ever from where there's an extra inch of sleave to positioning of the bag strap to the bag. Now think for a moment and consider everything you've bought