Reminds me of when I first taught at Berklee College of Music in the late 70's. The president, Lee Berk, was known to say "hey you're musicians, you're lucky to have a job at all." It paid terribly and our contact hours were ridiculously high.
Guess what happened? The Instructors unionized. Now they make good money, the College is extremely profitable too.
Ski Instructors have absolutely no "hand" so to speak, and the resorts take advantage of it due to their control of the means of production (the slope.)
Does this happen on golf courses too? Do they control who can teach on the course? How about tennis courts?
No competition allowed combined with no professional association or union that looks out for the member's wages.
Berklee now attracts high quality teachers, provides a better product and makes more money than they did when they were "doing a bunch of jazz musicians a favor by letting them teach."