The issue is that you are actually rejecting the things that make RPGs RPGs in favour of trying to classify everything as an RPG.
there is really no discussion to have with you on this.
Lol he is actually giving you well defined arguments on what is classified as an RPG, but you can't counter so you say there is no discussion. Personally, I find Ayvah's arguments interesting. He also makes excellent points in regards to the personal bias of some in their definition of what is RPG.
No, they are implying that every game would be a role playing game because you "take on a role" ... We call that a "blanket statement" in critical circles. They are a logical fallacy.
Role Playing Games are a specific genre of game. Just like Simulations are a specific genre of game.
D&D was unique at its time for BLENDING the two. One of the first, and probably the most successful, game to do so. Instead of being the general of your strategic tactical army, you were one of the soldiers or adventurers. Of course there is overlap. Just like there is overlap between Suspense and Horror genres ... but they still aren't the same thing.
The key difference is LITERALLY IN THE NAMES OF THE GENRES.
Simulation SIMULATES action in an autonomic way that the player adjust to achieve a desired outcome. The player has direct control over ALL actors that work towards that outcome. Simulations aim to portray a fantastical series of events in a modern presentation or setting.
Role playing does not simulate action, the player takes direct action. They do not have control over any actor but their own. You PLAY A ROLE - importantly, of your own creation.
You are right that I wouldn't call Witcher a role playing game. It's an action Adventure game. You do not choose or create your character. You are given one.
