I kinda skimmed through that conversation, but, if I may, aren't you taking Tolkien's work a tad too seriously ? I mean, a tad too realistically or historically ? They are fairy tales, they have evil species like other fairy tales have devils, demons, stuff like that : baddies who are the incarnation of baddies, and to whom the logic of free will, morality, diversity, etc, don't apply.
If Lord of the Rings is a fairy tale, then practically every work of fantasy is a fairy tale.
That devils, demons, and other species exist in fairy tales is irrelevant to their existence in other forms of fantasy. And LotR isn't a fairy tale. From a Doylist perspective, it isn't structured like one, nor was it intended to be written as one. From a Watsonian perspective, Arda operates under pretty concrete rules, with defined histories, cultures, etc. Fairy tales are far looser with their worldbuilding, far shorter, and don't really exist as defined texts (e.g. there's countless versions of Cinderella, Snow White, etc., there's only been one definitive primary source for Lord of the Rings.) The closest Middle-earth ever gets to a fairy tale is 'The Hobbit', and even that, I wouldn't call a fairy tale, given its length, its versimilitude, and that in the greater context of the setting, it's a series of events that definitively happened.
These are real life concepts for real life people, or real life group of people. Fantasy worlds aren't duplicates of that, they aren't structured like ours.
Not really. Fantasy worlds can operate on whatever rules they want. Some fantasy worlds are our world with fantastical elements (low fantasy), others are their own unique settings (high fantasy). Fantasy settings can take inspiration from the real world (some moreso than others), some have hardly anything to do with it. But if we're talking about structure, yes, a good fantasy (or sci-fi) setting generally has structure - rules to inform the reader as to what's possible and what isn't. Back to the fairy tale analogy, that's another distinction, because fairy tales don't really bother with worldbuilding.
Fantasy worlds are magical, they have zombies that eat without shitting, they have skeletons who talk without glottis, they have predatory ghosts of formerly loving people,
All true, but-
these are all dreamlike concepts, absurd reductions, incarnated contradictions, and that's their values.
This isn't.
First, all the examples you've cited aren't exclusive to fantasy. You can find ghosts in the supernatural genre, zombies in the sci-fi genre, etc.
Second, "dreamlike?" No, not really. That depends on the text. You can tell a story where these things are metaphors, and/or may or may not be real, but you can just as easily (heck, I'd argue more easily) make them concrete, definitive entities. Zombies alone, for instance, may be a metaphor for something in a work of fiction, but in the fiction itself, are definitive entities with definitive rules.
Orcs are Michael Myers : pure boogeymen, big bad wolves just like witches and vampires in stories where they are. And they are complex and varied in stories where they aren't.
Um, yes? That's kind of my point. That a fantastical creature is presented in one way in one story is irrelevant to how it's presented in another story.
It's "the evil in people" as seen through a child's eyes. And Tolkien's world, its whole poetry, is essentially this at the roots : the sublimed impressions of a child.
Completely disagree.
First, there's hardly any children in LotR (and certainly no POV characters), and hardly any see orcs. And if we're talking about the audience, how many children have read Lord of the Rings, and more importantly, who were able to slog through it?
Second, it doesn't matter whose 'eyes' are seeing the orcs, their actions and motivations remain the same. There's nothing in the entire Legendarium to suggest that when it comes to the orcs (or anything really), what we're seeing isn't the truth of the matter. There's no indication that we have an unreliable narrator.
Third, Tolkien's creative process for LotR is well documented, none of it strikes me as "the sublimed impressions of a child." Children generally don't spend their time in Oxford crafting English mythology on the basis that pre-Arthurian mythology had been wiped out, nor picking and choosing inspriations from other mythologies (Norse and Abrahamic come to mind).
Fourth, again, LotR isn't a children's story. This is maybe a cheap shot, but contrast Lord of the Rings with Chronicles of Narnia. CoN, you could reasonably call a fairy tale, given its style of language and lack of focus on worldbuilding, to the extent that some elements don't make sense (if Jadis is so worried about humans, why is she more worried about humans coming from Earth than coming north from Archenland? Furthermore, how the hell did Frank and Helen even populate Archenland so quickly?). LotR, on the other hand, is highly invested in worldbuilding - nations, cultures, races, languages, etc., and its style of writing is presented as something definitive that happened.
In short it's a mythology. A cartography of pure abstractions, as an environment in which some true characters carve a path.
Again, disagree. LotR isn't abstract. There's very little in it that's abstract.
Expecting everywhere similarities with our world is a fool's errand : there isn't, there doesn't have to, it's just written like that.
Well first, if I'm reading fantasy, I generally expect to see similarities to the real world, as writers live and write in the real world, and subconciously or not, tend to take inspiration from the real world. Sometimes more explicitly than others, but the inspirations are there.
Second, regardless of what similarities I may or may not expect from Lord of the Rings, it doesn't change the fact that the similarities/inspirations are there. Look at any element of Arda, you'll generally find a real-world antecedent.
And it's not a flaw, it's a genre.
Um, yes? That's kind of my point. Fantasy tends to take inspiration from the real world, because it's written in the real world. That's not a problem.