I am. I most associate it with Emerikol, although maybe others talk about it. It's more than just HP/meat, if I understand it. It's a basic "all metagame mechanics are bad", with an example being limited-use martial powers. E.g., if a Fighter can swing his sword in a circle and hit every target within 5', it requires metagame mechanics to limit how frequently he can do that.
And I agree with you: it's preference dressed up as theory, and it's nonsense.
And, for what it's worth, I think this whole complicated theory you've developed (not just "Primacy of Magic" but also your rationalizations for why "superhuman" is clearly delineated from "supernatural", etc.) is more of the same: preference dressed up as theory, to give it an air of objective truth.
I have a different definition: a disassociated mechanic is where a person at the table takes an action that affects the in-game world without a corresponding in-game action occurring or where such an in-game action is a post-hoc justification for the event.
Swinging your sword and hitting a lot of people? Interesting manoeuvre! Totally associated.
Playing a Whimsy card (Unexpected Ally) and saying "The person walking into the tense bar is a great friend and decent at bar fights!" Totally disassociated.