My idea is this: people often complain that demihumans are, like Star Trek aliens, usually just human beings but with rubber heads. There are often vague notions like "dwarves don't like the sea" and "elves are good with magic" but nothing much more interesting or detailed than that. -noisms
Demihumans are something I've been thinking a lot about in the last week, and this really sums it up for me nicely. Almost universally, the demihumans in nearly any fantasy setting are just human+(trait). Elves are petite humans who love nature and are good with magic. Halflings are tiny humans who are sneaky and brave. Dwarves are stocky, bearded humans who live underground.
As an American, I've been taught from a young age that the Chinese are good at math (INT+2), Jews are rich (x2 starting money) and African-Americans are great at sports (Free training in Athletics). Are these offensive, untrue generalizations,? ABSOLUTELY, PLEASE DON'T EMAIL ME ABOUT THEM. But in Dungeons & Dragons, there isn't any reason why generalizations couldn't be true. If there is a culture of doughty warriors who love beards, ale and warhammers, maybe they are famed for being tough and hardy (CON+2) and also known for their practicality and their strength (WIS+2/STR+2).Now, yes, this dwarfish human culture might be completely identical to normal dwarves on a character sheet, but does that in any way detract from the setting? Other than being a little taller and a little thinner, they fill the exact same "ecological niche" that dwarves do. In fact, they actually seem MORE interesting, because why are humans living in underground cities in the first place?
It's easy to fall into the trap of thinking that, due to Dungeons & Dragons being a fantasy setting, why NOT have dwarves? It's a fantasy setting, so there should be magic and dwarves and dragons, etc. Well, the problem with that argument is that, while certainly a valid opinion, it is an excuse, not a reason. It's the same sort of argument that Grognards use to talk about "wizard supremacy."
Perhaps, as a history major, I am biased. I'm so used to studying and identifying cultural groups from different time periods, that I already put human cultures in neat little boxes with ascribed traits, in a way that most people do not. I don't think that D&Ds history of assuming that humanities defining characteristic as versatility is accurate. Certainly as a species, yes, but as a culture? Especially historically, before the information age, this was just not particularly true. Just a few hundred years ago, the differences between people from two different cultures was vast. As far as I can tell, the only argument in favor of demihumans is that it allows the players to explore racism without real races. "Kenyan's are good runners" is really no different than saying "Elves are good runners (DEX +2)", and yet one is racist and another is not. And yet, by the same note, saying that "Humans from the kingdom of Elffe are good runners (DEX +2)" should work just as well.