>>> Wondering why this sort of gear does not get more use in the USA?
Very good question. This is exactly the type of gear that I like to use. Actually, I like to use even lighter gear: plain Nordic gear, with SNS bindings (not BC) along with waxless, non-metal edge skis. The skis aren't meant for track skiing, nor are they meant for black diamond runs. They are meant for touring. I usually take them out on logging roads (of which there are many around here) and occasionally back country. When I do ski back country, I occasionally use NNN BC gear, and occasionally non BC. In either case, I have by far the flimsiest gear on the mountain (and, I would imagine, the lightest). This means that if the conditions are poor (and they often are) then I struggle (I'm not a great skier and I'm not that young anymore). But it is really nice to just glide around in terrain like this: http://www.flickr.com/photos/rossbl/4461769222, even if it means I have trouble with the steep parts (I usually do a lot of traversing — at worse I just plunge step down).
I think there are several reasons why what I wear is not that popular:
1) Not extreme. OK, to a certain extent it is extreme, in that you are trying to push the limits of your gear — but it isn't the extreme that gets you on a Mountain Dew commercial.
2) Ski touring in general isn't that popular. Roger, that picture makes my mouth water. I would love to ski that terrain. However, not that many people like to do that on skis. Way more people like to take a lift. Those that avoid the lifts are often just looking for that perfect (very steep) run. On the other side you have folks that like going very fast on very light cross country gear. Many of the people who like to get out there use snow shoes, instead of skis. I'm lucky, in that there are great books (published by the Mountaineers) about the Northwest U. S. that cover exactly the type of skiing I like to do, even though we have some of the worst snow and toughest terrain around (to be fair, our terrain could best be described as varied — so we do have some easy stuff). Similar books exist for the Sierras, but I think they are no longer published. I haven't found anything about such skiing in Utah, Colorado, Wyoming or Montana. Likewise with the magazines (a couple cover Nordic groomed and a few cover extreme back country, but nothing for touring).
3) A lot of folks transition to back country skiing from lift skiing. They are pretty good (or great) alpine (parallel) skiers. They want the control that a stiff boot and a heavy ski gives them.
4) People prepare for the worst conditions they may experience. If 90% of the terrain is mellow, but 10% is steep, they bring the gear for the steep part. This, despite the obvious fact that they could just hike up or hike down the steep part. To a certain extent, this is true of traditional backpacking as well. Which brings me to my last point.
5) Pioneers are few in every pursuit. Twenty years ago, I hiked in running shoes. Other hikers thought I was nuts. Now, I'm just part of the ultralight crowd. I'm sure that someone, someday will make using really light, comfortable gear for ski touring popular. Until then, I will look unusual in my own country (but, apparently, right at home in Australia).