On the other hand if someone comes from a background where they feel oppressed, they're going to write that into their work.
That's part of the point of the article. People continue to extrapolate from what they view culture currently is, as if it continues indefinitely into the future. I think based on that "white men" are going to view it as being more pleasant and fair (i.e. their own experience) than minorities.
Or, well, pessimistic at all. One of the weird things about the post-war West is most people honestly expect the future to be better.
So "impossible to imagine" strikes me as an uncharitable characterization. I can imagine that vegetarianism becomes a moral norm, and I can imagine how the change could happen, but that's entirely disconnected from my doubt it will happen. I also remember the time in my life when gay rights weren't the foregone conclusion they've been for the last 10 years.
If we look at the distribution of shifting societal attitudes, there is going to be some threshold that turns things from "wishful thinking" to "probably going to happen." Without knowing what the information available at the time, and methodology used was generate the prediction, lying any blame at the feet of white/male/rich strikes me as applying a currently politically fashionable one size fits all explanation.
It may be a generalisation, but it's pretty accurate generally. — [citation needed]
The rich won't envision a future with less (or more) poverty. — [citation needed]
White men are less likely to imagine a future with full gender equality and black liberation than black women are — [citation needed]
People living in the West will think less about the rise of the rest of the world. — [citation needed]