I just realized that RWBY doesn't really have any ethnic groups or at least ethnic groups besides asian, whites, and africans. I mean the writers have already clarified that Remnant isn't really a direct parallel to earth. But they could at least try, right?
I don't think the show does all that well with what it has used.
It's an issue with worldbuilding overall.
Like, for example. People of color exist. Why is Vale mostly white? Why is the entire main cast white? Why are the Kingdoms so homogeneous overall?
The dynamics we have in our world are primarily dictated by historical and social events. Things like natural disasters, wars, colonialism, slavery, and even the crusades have influenced the way our world is. It has directly impacted things like how various ethnicities have spread through the world, the poverty and technological states of various countries, etc.
Yet Vale is clearly western-coded, and Mistral, despite having been implied to be a mix of at least Eastern and Mediterranean cultures, is primarily eastern-coded. Hell, the core "foundation myth" the show retconed into the story can't escape the pseudo-evangelical coding either, down to judgment day, humanity being "incomplete", as well as incredibly annoying "born again" allegories in Volume 9. And now the "final confrontation" is set to be on the plains of a desert city as people who already live there are forced to "take in" displaced nation.
Even ignoring how somehow Remnant's social issues are limited to one kind of discrimination (which makes zero sense considering Atlas, Great War, Upper Class District in Vale, Cinder's backstory, SDC, a literal Robin Hood character, etc), the worldbuilding of Kingdoms and cultures there lacks coherence. If Remnant is not a direct parallel, what events would have influenced the dynamics there, then?
If there were none, then shouldn't the cast be more diverse overall? (This also applies to how heteronormative the show is for most of its run. Because if "there's no discrimination other than Faunus discrimination", then why is the world portrayed as so heternormative? Where's LGBTQ+ rep? Aroace characters? Pansexual? Bisexual? Trans rep beyond a fumbled allegory with Penny?) Shouldn't the Kingdoms truly be a mix of various cultures, beliefs, myths, and ethnicities, then? Shouldn't the writing do better than "Flynt Coal"?
Is there a reason within worldbuilding for that, or is there not?
It would also have been pretty easy to fix. Not to mention interesting to fix. Thinking through details like that provides storytelling opportunities.
One of the first things I have conveyed in my rewrite is that discrimination isn't always just about Faunus. Societies and communities shift their focus all the time. Atlas is defined by socioeconomic inequality, and the rich and powerful hold all the power there. Mistral is heavily classist and unable to let go of the past. And while people of Vale would proudly proclaim to be beyond such concepts, their own history had one of their kings ordering the destruction of another kingdom, painting them as convenient scapegoats due to the color of their skin. All that, as well as different histories of each Kingdom, influenced the social structures there. Likewise, the Faunus situation had a clear beginning from which the discriminatory dynamic evolved. All of those things can then become building blocks for plotlines and characterization.
So why does the canon ignore developing those worldbuilding elements? I think it's for the same reason they do nothing with the Great War, and why they kind of fumbled the Faunus subplot and the SDC subplot and Atlas and other things.
I think in a lot of ways, for the show, it's an issue of not having a consistent, professional, and diverse writers' room. Why is the show so heteronormative for most of its run? Why does it not have a more diverse cast of characters? Why does it not convey a truly diverse and unique world? Why does it fumble allegories like Penny, or write in problematic things like Ironwood's semblance and the entirety of Volume 9? Because it's written by a bunch of guys from Texas. A bunch of guys from Texas who likely couldn't perceive those issues or didn't care. A bunch of guys from Texas who didn't hire sensitivity readers or a proper writers' room, so nobody would point out those issues to them. A bunch of guys from Texas who are really bad at handling criticism constructively and would rather write a strawman of their critics as V9 villain, M.Night-Shyamalan style.
Or maybe it wasn't even a priority, just like many things the show could have delved into or done better. What was the priority then? Going by how the show is written—all the clickbait decisions like Penny revival, all the lack of progression and consequences, the inability to address the end of V3, character dynamics never evolving—the priority likely was to keep going for as long as they can and nothing else.