Im sorry you feel that way, because it is not my perception at all.
Maybe the forums have changed since you last visited?...I think Ive only seen 1 post about PSIA vs. PMTS, and actually harald stops most of those threads fairly quickly. I tend to see more of the PSIA vs PMTS vs Whatever Else on the generic forums then on the PMTS forums. Primarily because I think most people at PMTS could care less, all they seem to care about is improving skiing technique and helping each other improve.
Actually in the last couple of weeks, we've had some awesome discussions on speed control, short radius turns, and stance questions. The best threads we have are the ones where people are brave enough to post their video of skiing and has everyone analyzing them. There is no better way to learn than to try your best at analyzing another skier, then having a qualified person do the same analysis so you can see what you picked up on and what you missed. This helps thoroughly when your skiing because then its in your mind what you have to focus on.
The difficult thing for me with other "generic" forums is that you have several schools of thought posting responses about lets say transition. You can't get 1 straight answer and your head often times comes out spinning with all of the responses and the beginner/intermediate who asked the question is left to decide which is the best technique. Is this really the best way for a learning skier?
I have yet to find another skiing forums that has so many posts on technique instead of where people are going skiing and what gear they have. Maybe Im a bit different, but I really dont care where total strangers are going skiing, but I'll read every single post I can find on skiing techniques...which unfortunately sometimes a little sparse on some skiing forums.