Yes, you are correct, this is something that you be either taught to racers, or very advanced skiers were racer type skills would be the next step and a benefit. Even in our group back then we had about 1/3 the class refuse to do it (our instructor said that this was optional but worth the effort), 1/2 attempt it once, the rest got it after an attempt or two, one did it without problems (he was a higher level instructor from Ontario just brushing up his skills).
I must say we had an extremely strong (easily into the expert range) group of skiers in that group. What was amazing is how far the instructor pushed us well beyond our perceived limits along with the variety of skills improved in a 4 day package. I was extremely good when I started, and greatly improved when I finished (everything got tweaked that needed tweaking). Instructors like that are one in million (no offense to the instructors on this site).