Once you analyze and answer that question, I think you'll see why there is a movement away from "on your knees" and towards "prone from the beginning."
The point of my question of course being that I was unaware of any movement.
Of course once you develop past open water I had seen this prone position employed for teaching and practising skills, however I was taught that for beginner divers the best position to keep my students in a semi circle around me on their knees.
This is not to say I agree, it was simply a question as I was unaware of any 'movement' and like I said, I like to keep on top of the best methods to teaching and I am always open to learning and adjusting my skill set to incorporate what I learn, we never stop learning, particularly in this sport. Well I dont anyway. I am a new(ish) instructor and would hate to think my students weren't being taught efficiently because I didnt investigate other teaching methods.
I agree that of course it makes sense to teach students the skills in the position to which, if they ever need to in a real situation, they will be performing them. However my CD taught the kneeling semi circle approach as the best method to keep control. I believe the reasoning given was that kneeling provided the instructor the greatest controls to keep brand new divers stable and in one position.
Next class I take I will try the prone position