"We have to uphold fictional racism based on real racism in order to be historically accurate" will never not be a terrible argument. A lot of white characters are white because the default was white. It has nothing to do with historical demographics or anything.

As always, what they're really mad at is the very thing they love which is capitalism. Capitalism is the reason why the default was white and it's also the reason why there is now "forced" diversity. They have white people's money, now they want to go after everyone else. That means appealing to other kinds of people. Communism would also produce diversity in media, but for entirely different reasons.

Under communism (with the proper intersectionality) wouldn't have had a white default to begin with. You would have already had a variety of cultural stories in the mainstream because there wouldn't have been a profit-motive for making everyone white. Other ideas would have been able to come to the surface because people could create without having to worry about market shares.

These companies enforced the racial bias its now trying to solve. Which is exactly why they won't be able to solve it by continuing to do business. It's just going to create this kind of culture war stuff because they refuse to address the historical problem and solve it in a way that will actually work. It's still about profit, just not profit from whitey.