Looking through my Steam games list, the games with the most generic stories and worlds are also the ones that have the most boring cast of characters. It seems that if writers take time to flesh out the world they are creating, then diversity of culture, race and history occur naturally. The four games that pop in my head first when i think of a well fleshed out world are: The Last of Us, Half-Life 2, The Walking Dead and Mirrors Edge. And, not-so-coincidentally, these games all have quite a diverse set of main characters.
The same is true for the Assassins Creed series. The games are built on the idea that you can experience the culture, people and history of a certain location and era, so it makes sense that they would also include the ones that the author of the article appreciates the most.
Maybe the way to obtain more of what the author wants (which sounds like more ethnic diversity in game characters) is for developers to put a greater emphasis on world-building, pacing, and explaining the story rather than gameplay and graphics. I personally would be very happy with that because other than CSGO, good stories are the only reason I play games anymore, and although the AS franchise does good on certain things such as world building and exploration, it has failed horribly at creating an engaging story for a majority of its games (go here, kill this person you don't care about, go over there and pick up this item you don't care about, etc...)