I would argue that the Witcher 3 is not an RPG but an action game with rpg elements.
And I would vigorously disagree. But ultimately what matters is that none of us has copyrights over the term RPG, and, as @Madscientist says very well, the definitions don't matter so much as whether we enjoy a particular game or not. I love the "RPG" genre almost exclusively for my video gaming preferences. Hard to argue Ps:T is not an RPG. And yet, I don't care much for Ps:T and personally view it as an overrated game. We all have our weirdnesses and our peculiarities.
Sorry, but this is the internet and therefore I cannot abide your personal opinion on PS:T being considered anything less than a masterpiece. You have offended my good sensibilities and the general standards of public decency. I demand satisfaction. Pistols at dawn.
Anyway, I find the debate over what games are considered to be RPGs generally pretty tedious. Some people say The Witcher 3 isn’t an RPG because it doesn’t have deep mechanics and customization, some say Diablo 2 isn’t an RPG because it doesn’t have an interactive story, and some say Final Fantasy games aren’t RPGs because they have neither of these features. While I wouldn’t say it is always the case, what I generally observe is that what people are really saying is that “the games that others call RPGs and that I don’t like are not RPGs.” I personally don’t like The Witcher games, don’t generally like top-down Diablo style ARPGs and can count the number of JRPGs I like on the fingers of one hand, but I’m very comfortable saying these are all different flavors of a single, incredibly diverse genre, as long as we can all agree that The Legend of Zelda is not an RPG.
