That's true, but it illustrates a key issue with RPGs like D&D, where players are often expected to solve problems rationally, in a universe full of bizarre fantasy elements that only make sense in more "magic realism" or "metaphorical" context.
Sometimes that conflict is a lot of fun in the way you saw in some novels (particularly in the '80s), where someone just comes along and "sorts out" a fantasy world (you also get this a bit in Terry Pratchett) with Facts and Logic.
Ironically enough, lot of modern fantasy RPGs (and some older ones, like Pendragon and Heroquest, but they're in the minority) do manage to handle this gracefully, but D&D has always had some peculiar issues here. It doesn't help at all that D&D stole its magic system and general approach to magic from a series of what are basically sci-fi novels/short stories (something I'd say with a lot of confidence having read them a while back), which have a very science-y kind of magic in them, and totally failed to import the mysticism and weirdness of even Tolkien.