Disclaimer: I haven’t played the game, but I read all the books in original Polish.
There’s also the problem of (perceived or actual) misogyny in the game. From what I gather (and know about the source material), there are certainly characters that are violent and condescending towards women. But they are usually evil in every other aspect too, and the main character has options of dealing with them, and other NPCs also recognize them as assholes. And in that world, women actually hold a lot of power as sorceresses and queens.
As a person born, raised and living in the country and culture that produced The Witcher books and the games inspired by them, I am really not surprised.
I know that argument about historical accuracy is a tired one, and not entirely applicable when it comes to fantasy and sci-fi. But for me, it rings true in this case.
The game is a product of mostly Polish minds, based on the works of a Polish author, using Slavic mythology with some Germanic and Celtic elements thrown in for good measure. Poland (and, frankly, most of the Central/Eastern Europe) was and is very much a racially homogeneous country, and even in the biggest cities, seeing People of Color is pretty rare. All of this clearly shows both in Sapkowski’s books and in the games.
I’d also argue that, considering troves of Anglo-Saxon-centric entertainment, depicting elements of Slavic culture and mythology is a step towards diversity. It just so happens that Slavic people have pale skin.
What’s more, all of the games revolve about social and racial tensions between the rich and the poor, the humans and non-human elves and dwarves, outsiders like sorcerers and witchers. It’s a thinly veiled allegory, replacing the color of the skin with other characteristics. Besides, there are racial tensions in modern-day Europe, where migrants from poorer countries like Poland, Ukraine, Romania or Serbia are stereotyped and discriminated against in Germany or the UK.
Sure, there are non-white people in the world of The Witcher that could have been included. It can be argued that developers should have done that. They chose not to, maybe because that would look like including token minorities? Should they include something they know next to nothing about and risk enforcing racial stereotypes in an effort to appease the crowds? On the other hand, artistic license exists. That’s a point worth discussing, I think.
I recommend reading this polemic to the Polygon review by Polish game developer Adrian Chmielarz, who goes over these points with a lot more eloquence than I.