Does the American Dental Association argue for better pay for dentists? Does the Screen Actors Guild train actors how to act better?
The vast majority of ski instructor training that occurs in the US is done in house and is not conducted by PSIA staff. As a trainer at my home resort, I'm right in the middle of this. I took 4 days of PSIA training this past season. I taught clinics or did 1 on 1 coaching of pros nearly every day of the season. Most of what I taught was just me rehashing my own version of what I was taught by PSIA/AASI (the snowboard side of PSIA). Some of the instruction taught to pros at my resort was material that was based on PSIA, but then customized by the particular desires of the training manager for that discipline. A large part of what we trainers teach is system agnostic. Areas like safety, group handling, movement analysis, feedback, bag of tricks drills, lesson structure, lesson procedures are mostly "system" agnostic. So although it is true that most ski lessons taught in the US are taught according to the tenets of PSIASki schools (including schools that are PSIA member schools) are free to choose whatever system they want to base their training on. Between other national based systems and independently branded systems there are plenty of alternatives to PSIA. The biggest reason why none of these alternatives have replaced PSIA or even risen to the point where they are a competitive alternative is "economy of scale". Other systems may or may not be better than PSIA, but until they are significantly better they can't deliver enough value to overcome the economies of scale that PSIA offers. Canada, Switzerland, Austria and Australia all have fine national systems. I would not mind changing my teaching approach to comply to these systems because it wouldn't be that much of a change. There is one alternative non-resort specific teaching system available in the US. I would mind changing my teaching approach to comply with that system because I know enough about it to question how the areas that don't overlap would work better than what I do currently. Those questions come from direct experience with some of the concepts that are central to that alternative. There is enough dissatisfaction within PSIA that if that alternative was as revolutionary as it claimed to be, it would be a lot more widespread than it currently is.
If I wanted to work on my ski technique outside of PSIA there are a ton of alternatives (e.g. NASTC, Skiclinics, Steep and Deep, Windells). If I was smart I could probably learn a lot about teaching from those "camp" type products too. I've chosen PSIA for my personal training because the price is right and the quality is good enough.
PSIA does come up with ideas for better pay and better HR. I attended a PSIA-E training event this year called "Ski School Management Seminar". Although there was some top down transfer of information, the bulk of this experience was sharing information and ideas with leaders from other resorts. Although this was my first time attending this event (I'm still not in management and I went to it to get training focused ideas), the event has a long history.