I don't mind realistic "diversity", it is unrealistic "diversity" that is actually propaganda that bothers/annoys me and I think that is what many other people are trying to say. Just turn the situation around and the ridiculousness of it should become clear to everyone.
What if someone made a game, or movie, or book, etc, about Shaka Zulu and the war against England. And what if half of Shaka's warriors were white women? The "diversity" crowd would be in an uproar over white people being put into that story. It's really just reverse racism. The "diversity" crowd supports putting people of color into situations where they don't belong, and then become outraged if white people are put into situations where they don't belong.
Their arguments are not honest. In reality, they just hate white people. I am not a racist person, and my own story had "realistic diversity" and a female hero character 20 years before that became a thing. There is a difference between "realistic diversity" and reverse racism disguised as diversity.
As an example of what I mean by "realistic diversity", in my own sci-fi universe my version of the Federation Star Fleet, the human "space navy", is dominated by people from nations such as the United States, Russia, England, China, Brazil, India... nations with both large populations and a history of voluntary military service. This makes sense. It would not make sense for the human "space navy" to be dominated by people from Angola, Indonesia, and Micronesia. There aren't enough of them and their nations have no history of voluntary military service or leading the world in cutting edge technologies. It has nothing to do with racism, it has to do with the reality of the world.
It's not racism that annoys many people when "diversity" is forced upon us, it is the unrealistic nature of it that makes it feel (and often is) as though you the creators of that material are trying to literally brainwash you with obviously incorrect propaganda.