As a person of color who actually wouldn't mind good minority representation, (one of the main reasons I love AC.) I cannot stand when people pick and choose games that don't support their argument but instead make the argument a target for the opposing side as it makes us look uninformed. The writer of this article in particular states that the world of Bioshock and the Witcher have real world counterparts. If you would consider Poland to be the Witcher's real world counterpart then you would be admitting to knowing nothing about Poland considering that this is what amounts to their racial diversity.
Polish 96.7%, German 0.4%, Belorussian 0.1% Ukrainian 0.1%, other 2.7% (2002)
Read more: Ethnicity and Race by Countries
http://www.infoplease.com/ipa/A0855617.html#ixzz3TLuwGvFT
It's most certainly not a diverse place. And the other obvious point, um, news flash, Rapture and Columbia don't have real world counterparts, and both are set in the past and address racism as an issue..