I have a question I can't seem to answer, or an answer I don't understand. So please bare with me (please and thank you).
If all these ancestries have lived together long enough to build a cohesive bonded culture where no one ancestry has a unique culture or socio-economic class or job pattern or skill pattern, how does that work in a timeline? I mean, assuming we're going off real-world dynamics (which we are, because if we aren't then the fantasy world not mirroring real world would be a valid argument), then why are the races not homogenized? There is no way it would be as heterogenous as it is, with dozens of races running around. Unless of course, they chose to be separate, which would lead to certain groups being lower or higher than the other.
Now, if we go from the standpoint that pockets of races live with only one another (elves in the forest, etc.), then wouldn't some of their behavior be dictated by societal rules? Isn't it possible that in one society there are more law abiding citizens than in another? Isn't it possible, due to geography, resource scarcity, corrupt people in power, that one society might be more warlike than another? Isn't it possible that all the way down to how they raise their children might be worlds apart? If a child grows up without having been taught how to empathize, then there is a a greater chance they don't harbor the same feelings as one that does.
If we view the D&D world as somewhat realistic and taken from history, then I'd suggest watching the Primary Source videos from Voices of the Past. They do a great job with teaching an understanding about historical context from readings of first hand accounts and journals. They sometimes note the stereotypes of the time, but more the differences as a whole. And many of these differences are the way groups act.
www.bing.com
Sorry, I am just having a hard time making sense of a timeline where everyone is different, yet groups have never pooled or formed, despite being different phenotypes. If it is all based on individuals, then all the races would have melded to one provided they can procreate, which many can because we have half-orcs and half-elves.
And please, no one take this as a stance on "he's against change" or "he doesn't recognize real world plight" or anything else as ridiculous. It is a question regarding the timeline of creating different ancestries, yet not creating cultures that dictate behavior or eventually blending.