Nolo, I believe that one characteristic many of the "have nots" share is a lack of proper instruction at the lower levels. Regardless of their intent, athletic ability, desire, time, or any of the other things mentioned, most of them lack the "accuracy of stance" that Ski&Golf described.
They exhibit a stiff outside leg, or an outside hip that's too high and forward, or an upper body inclination into the turn, or too much rotation, or lack of independent leg action, or a lack of fluid rhythm, or poor hand position, or some combination of all of these. At the skier's advanced intermediate level these may be very subtle, but they exist nonetheless. And they surely and certainly inhibit any chances of becoming a truly "dynamic parallel" skier.
As you know, Nolo, as well as anyone, at this level these bad habits can be extremely difficult to replace with more effective movement patterns, even if the skier recognizes and acknowledges them and seeks instruction to try to overcome them.
Many of these habits develop on their own in self-taught skiers. Unfortunately, they also happen in skiers who have consistently taken lessons because, I think, of the poor quality of instruction given at lower levels.
The misguided belief and practice on the part of so many ski schools that the less experienced instructors should teach the beginners and lower level classes often results in instructors overlooking or even tolerating the developing bad habits because they, the instructors, don't understand that they are laying a foundation for all of the learning and progress to come. Too many of these instructors have no frame of reference to allow them to put the basic skills, good or bad, that their students are learning into a more advanced context.
One problem is that bad habits such as those I listed above don't necessarily inhibit skiing at the lower levels. The student can still believe tht he or she is making progress because the stiff outside leg or the hip in the wrong position don't stop them from skiing. So they become ingrained and tolerated. Progress is measured in terms of more difficult terrain rather than in skills. Eventually the skier tries some terrain that truly requires proper skills to ski comfortably, and the skier is NOT comfortable. And then learning, desire, intent, can all stop.
[ February 07, 2004, 06:57 PM: Message edited by: David7 ]