Oh well, as you put it so authoritively, I should accept that what you say must be true, shouldn't I?
I should add that I have found that people who express themselves with arrogant and condescending assurance are at least sometimes themselves in error.
So, if it's alright with you, I will continue to think for myself, and treat language as the continuously evolving entity that it most certainly is (please excuse my arrogance in saying so), not attempt to place language in an amber prison, where many people seem to want to keep it.
Please understand that I'm not saying you are wrong in your assertion, only that nothing is ever certain in the field of human endeavours.
Sam

"Lasciate ogne speranza, voi ch'intrate" - 'Abandon all hope, ye who enter'.
Dante (Durante degli) Alighieri, "La Divina Commedia", "Inferno", c 1308-1321