Rick--a quick search of the archives here finds at least seven instances where a PMTS proponent has suggested that "lifting is learning; lightening is expert skiing." Indeed, one of them goes on to say: "Once a skier is taught to lift, the next step is not to lift...." I think it's quite easy to understand Learner's (and my) concern about teaching something that must then be untaught.
I do appreciate lifting a ski as a balance drill. As a DRILL, it has its uses. But as an integral part of a turn, especially when done as the first "step" of a new turn, it causes problems that can, indeed, become difficult to "unlearn." I can spot someone who learned this way from a mile away!
We've been over this ground many times before, and I am loath to retrace the tracks of our previous discussions. A quick search will bring up a page of links to the subject. But briefly, transferring weight to the uphill ski prior to making a turn (i.e. as the first move of a new turn) requires a movement of the center of mass uphill--in the wrong direction. This may not seem like a big deal, but it entirely disrupts the smooth, continuous flow of the body through the turn transition. Because the body does not move INTO the new turn, this move also, almost inevitably, causes the skier to push the uphill ski out into a skid, in order to get it out from under the body. This is not theory--it is a common mistake, nearly ubiquitous in skiers who have learned this way! Which is, I believe, Learner's point.
Furthermore, these critical problems are made worse by the inability to steer the feet, resulting from lifting one ski off the snow. As we've thoroughly and repeatedly discussed, with one foot off the snow, any torque applied by the skier to turn the other ski MUST involve the upper body (or swinging the lifted foot, an odd technique indeed!). The result is skidding, imprecision, and inability to sustain steering accuracy throughout the turn. The only other choice is NO steering--pure carving, railroad track-style, all the time--which is a very serious limitation, wouldn't you say? If you can't control your direction--PRECISELY--you are out of control!
Yes, weight transfer is a part of many turns. But doing it right is a question of subtle split-second timing, of the delicate but undeniable relationship of cause and effect. It's the difference between the weight transfer that takes place when you turn a car--BECAUSE you turn the car--and one that would occur because you told everyone in the car "lean left because we need to make a right turn." (That would, to say the least, be odd!) And on skis, it isn't just odd and unnecessary--a mis-timed weight transfer on skis carries many negative repercussions, as described above.
For an instructor, failure to understand the mechanics is not a good excuse for ignoring it!