His response
"I have actually tried that several times, in fact, and it doesn't make any difference in a turn. I can see where some skiers might think that they are turning with their ankles but, in reality, they are actually turning with their knees because their ankle is laterally immobilized by their boots. When somebody can show me how they edge their skis by moving their ankles without moving their knees, I will be a believer. Until then, not so much"
This is the only thing to say after a response like that.
“Never argue with an idiot. They will only bring you down to their level and beat you with experience.”
These so called instructors on other sites are 20 years behind the bio-mechanics of the PMTS instructor manual and 40 years behind current evolution of PMTS. They can't even begin to conceive what skiing is about when originating from the bottom of the kinetic chain, let alone understand how it also involves dominance of the movements generated from the inside half of the body for the next turn.
When your only way of turning is by steering and pivoting your thighs, you are like the craftsman who only has one tool, the hammer, and if you have only one way to think, as traditional instructors want to advocate; everything looks like a nail to you.