BING BING BING! This is what I've been talking about. The setting was written for the system, and therefore included what was in that system.
No! That's not how it works. Writing a setting for a system only includes what of that system the writer wanted to include, not EVERYTHING.
They do if they want me to spend $50+ on the setting. If I were to buy Dragonlance and discovered that out of all the standard D&D races, they failed to include one of them, and they didn't replace it with something as or more interesting, I'd want to know why.
Then don't buy it. If I see it and it's as sparse and terrible as a setting book as Spelljammer, I'm not buying it. If it's well done and includes every race under the sun, I'm also not buying it. I'm not going to spend another $50 on kitchen sink setting #471. They're going to need to curate things and give me something unique for me to spend money on a setting.
We all have our reasons for spending money or not.
Or did you forget we were talking about a product published by a major company and not your homebrew world? (generic your)
Nope. But why buy yet another generic setting from WotC when I already have multiples from them?
and orcs are actually an established mythical creature, originally a
"devil-corpse," although I fully realize that this may not have been known to Weiss and Hickman at the time.
I'm not sure how this is important? That's an undead creature that is nothing like orcs in D&D or Tolkien.
Why? Neither movie contains every other Tolkienesque trope like how Dragonlance does
Dragonlance does not. It doesn't have Eru(one god), Valar(archangels), Maia(angels), immortal elves with gifts of telepathy, far seeing, pass without trace and more, nor does it have dwarves that hate elves and vice versa for how the races treated each other, elves who were banished from heaven for heinous crimes, and on and on and on.
Hell, most of the "Tolkien" stuff it does have is just D&D stuff that originally drew on Tolkien for inspiration. It's not actually Tolkien at all.