It can be criticized, but if you criticize Witcher for lack of black people - why aren't you criticizing 7th samurais for the same?

you're not really going to try and use this tactic, are you? "well if you care about X, why aren't you also caring about Y? if you think X is bad, why aren't you also talking about how bad Y is?"

that's such a dishonest argument to use, especially since it presupposes that the person you're using it against doesn't have the ability to care about more than one thing at a time.

also, Seven Samurai came out in 1954 and was explicitly about 1587 Japan, and didn't include the fantasy element of teleporting to other worlds.

The Witcher is about The Witcher and (for the fiftieth time) I haven't seen a single official or academic source that confirms it is supposed to be set in 1200's Poland nor based upon that era of Poland, especially since other people seem to be saying it's actually about WWII which WWII wasn't in the 1200's so obviously something is up here.

even more so,

After seemingly being killed by a mob during a slaughter of non-humans at the end of the Witcher saga, Geralt's story continues in more recent computer games (The Witcher, The Witcher 2: Assassins of Kings and The Witcher 3: Wild Hunt). Geralt returns to life with no recollection of the details of his sudden reappearance. He is rescued by the last remaining witchers in the world and taken back to Kaer Morhen. It is hinted that in the game, he will reluctantly uncover a conspiracy concerning the Witchers. Note that the story of the game series is considered to be non-canon by Andrzej Sapkowski.[1]

is from the wiki and states the games are non-canon.

so a 2015 game that is inspired by a story that isn't set in poland, and is considered non-canon by that story's author, should be held to different standards than a 1954 movie explicitly set in 1587 Japan that didn't involve zombie babies, teleportation, or being brought back to life from the dead.

The problem is criticism from American POV that assumes every white author should follow American culture.

do you think only american culture is concerned with diversity? I mean, I've seen plenty of europeans criticize america's racism problem. can I tell them that they're being euro-centric and it's our right to be racist because that's our culture?

sorry, that's a dishonest argument on my part. when europeans criticize america's racism or lack of diversity, should I tell them that they're being euro-centric?

because I think we should realize that it's 2015, the game was made to be sold around the world and was in fact marketed to americans along with the rest of the world, so the game can be held to standards by the people the publishers and devs expect to buy the game.