I mean, I feel like it does give one answer why, but you're dismissing it out of hand much like all the other answers you've gotten in this thread. It seems you simply don't want to directly engage with the subtext of monsters (and themes as discussed above). That's fine and valid, but demanding other people justify their enjoyment of it while refusing to show them or their answers any respect is a good way to drive off conversation.
I Don't Know How Else To Tell You That Some People Like Telling Stories
fuck dnd for a minute cause i wouldn't play it if you paid me, and even forget the fact that as the most popular rpg there are so so so many people who want and would benefit from having more storytelling tools to tell the stories they want to tell in the system they want to use. fuck all that for a minute.
you're coming in here picking fights on every post in the "narrative tools" thread about how Narrative Tools Are Bad and youre So Angry That People Want Them. you're repeatedly dismissing people's legitimate opinions that, in a genre that is largely about telling stories, that people wanting tools to make games where the story isn't 'i found the cleverest way to solve this tactics/thought puzzle isn't my character cool' or 'let's get loot and kill goblins' or whatever, is a bad thing. i'm sorry you've declared some huge crusade against "story gamers" and i'm sorry that there aren't enough angry grognards here for your tastes but maybe let those of us interested in telling stories, talk about how to do that better, without jumping in on every post to say that it makes you so mad that people want to tell stories? maybe take a step back, my guy, and realize that maybe this conversation wasn't for you to begin with, and was for people interested in narrative tools and the construction of a hypothetical platonic session, like the OP said. if you want a groggy thread to rant against people telling stories, go do it somewhere else; picking haughty "debate me coward" fights repeatedly about "explain to me with logic why you like telling stories" over and over is clearly not productive, right now! take a walk, some deep breaths, and then if you wanna come back and treat people with respect and listen to them instead of fighting some strawman proxy fight please come back and hang out!
you're still picking fights about people daring to want to play games different from you but go off i guess
My understanding of your line of thinking, Axes&Orcs, is that you're presenting two points:
1. D&D is not (and is not intended to be) a game that's designed with narrative structure in mind. (And maybe 1a: If people want narrative structure there are better games out there.)
2. Because 1, creating space in the text of D&D for what we might call "narrative training tools" is unnecessary.
If those are accurate readings of your points, I agree with point 1 but I think point 2 is no hill to die on.
You're right that D&D was designed with particular goals in mind, a lot of people use D&D for stuff that's well beyond those goals (my feathers always get a bit ruffled when I hear "we played the best game of D&D ever last night... we never even picked up the dice!"), and those people might have an experience that's closer to their flavor of fun if they used a different game.
But for point 2, I feel like there's a lot of stuff in the D&D books that people never use (if we limit ourselves just to the PHB: travel, encumbrance, trade goods, underwater combat, etc.). To me, it doesn't feel like a betrayal of D&D's design if WOTC adds a few paragraphs (or even a whole chapter) on how narrative structure can be noticed and highlighted in the course of improvisational and/or tactical play.