Am I the only who feels who it's doing nothing but repeating the same things to the same arguments, time and again? 

Let's call it the Ouroboros of Unreason
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Ignoring those who cry 'political correctness' and 'racism', there's basically two viewpoints (consistent worldbuilding argument versus diversity / inclusion argument) that aren't so much opposed as that they follow two very different forms of logic.
In most fantasy universes, as in reality, they should be complementary. Thedas is highly unusual in the sense that it's a castrated, decolorized, isolated vague analogy of historical Europe. There are some examples in fantasy literature and particularly in (mostly American) pen & paper fantasy RPG settings, but they are actually pretty rare. There are good reasons for this, because most fantasy writers are at least vaguely aware of a wider world beyond Europe, that it interacted with Europe, and that incorporating this makes their world larger and more complete.
It wasn't always done because of political correctness; in fact, it's hard to argue R.E. Howard or Tolkien were modern-day liberals in that regard. But they understood the fact that if you want a diverse, rich, varied fictional world, it has to resemble our own in terms of size and variety.
When a setting wilfully ignores this general rule - for whatever reason - it feels 'wrong', and also makes it difficult to easily introduce this diversity afterwards. This is not so much because the creators don't want to, but because there are, ultimately, no compelling reasons to make them do this. Let's not beat about the bush: DA was created by an overwhelmingly white studio from a country that, until very recently, was overwhelmingly white*. It's a 'white' setting made by and for white people, with only the USA having a significant number of non-white gamers within EA's core markets.
I don't think it's a coincidence Rivain got retroactively 'Hammerfelled'; only 'black' gamers and their sympathizers (count me among them for inclusiveness reasons) really made a bit of a fuss about Thedas' susprisingly high degree of 'whiteness'.
What I mean is that BioWare isn't going to introduce new (and clearly non-European derived) human cultures and human phenotypes if there isn't significant gamer pressure behind it, regardless of the degree of sympathy individual devs like David Gaider may feel. There is no need. BioWare did Jade Empire and that game was a commercial disappointment. Why waste resources on non-traditional pseudo-Europan stuff if there's no real demand? That's only going to happen when gamers themselves, and in force, are going to demand diversity and actually reward it when implemented**. It doesn't really matter to what degree it requires retcons and special pleading, just that the pressure is exerted and Bioware acts upon it.
The movers and shakers at EA and BioWare aren't going to go along with this unless they see value in it, by way of either sales or very positive PR. People at BioWare themselves who are in favour of more diversity also need ammunition. They have to be able to point at gamer reactions (angry and / or reasonable, actual sales) to make their case.
*If I can trust Wikipedia in this, non-whites were barely 3% of Canada's population in the early '60s. That makes it almost as European as Europe itself at that time. It's a pretty safe bet this influences, even if only at an unconscious level, the way white Canadians experience and deal with issues like this. In this they are probably very different from Americans, where race has been an issue for a long time.
**Assuming it's at least a decent game, of course.