Because this is not Alice in Wonderland? Why does a completely fictional setting need gravity, or 24 hours long days, or basic physics, or simple common sense? It doesn't, and you could make a story without those things just fine, if that's what you wanted. But not for the sake of it.
"For the sake of it" is pretty much the only reason that fantasy fiction exists at all.
But not for the sake of it. Similarly, the DA team seemed to want a world that at least partially mirrored ours in matters of race. They could have gone with the opposite, but they didn't chose to, they likely didn't want to, and they have no obligation of any kind to do so.
Lol. Exactly what matters of race do you think are being "partially reflected"?
If someone created a "mirror" of our world that showed only white people, I would think that person was either racist or stunningly ignorant.
"They have no obligation" is such a weak-ass excuse. Like, if that's the best you can come up with, you should really just give up.
As a writer, I can vouch that I write my story the way I want, not the way my audience wants, and I care more about the setting than I do about issues of diversity and representation, even if they have their place. As part of the audience, I can say that what you find boring I can very much find interesting. I play DA to enjoy the story, the characters, and yes, the setting, not to see people like myself in the screen that were shoehorned because of some arbitrary sense of political correctness.
Thedas is what it is. If it is made into something else, then that is a retcon. Maybe that's not necessarily a bad thing, but that's most definitely a thing I'd want to avoid. But my point is diversity and/or representation are not the point of most if any stories. In most cases, how the black people got there is way more relevant, whether you like it or not.
As a writer myself, I'm not even vaguely interested in reading or creating settings that are not diverse. And I don't do it out of any sense of "political correctness". I do it because we have enough lily-white carbon copies of Middle Earth already, and because other cultures have a mostly untapped wealth of awesome myths and folklore from which I can draw inspiration.
Simply put, it makes my work stand out, and it makes me a better writer. The fact that it is also the right thing to do is just a bonus.
Do you realise that you just said you would avoid a retcon, even if it made your work better?
Diversity and representation are not the point of any of my stories, but does it follow then that all the important characters must be white by default? If race doesn't matter to the story, then what does it matter if the protagonist happens to be something other than white?