It doesn't seem like reason is going to win out here.
Somebody who picks a single narrow definition for a word and then applies that narrow definition to every instance even remotely related ( when other, more contextually correct definitions exist and have been pointed out ) isn't working with a full deck, intentionally or otherwise.
You can't reason somebody out of a position they didn't reason themselves in to.
In the same way you can't apply narrow definition for a word to all situations, when other more contextually correct definitions exist ?
(I mean, you can, but you probably shouldn't)
Also that is literally how languages change over time, so..yes, you can.
Though having a narrow definition of what a language can and can't be does track with your general vibe so far....