Earlier quoted context omitted.
And as someone far to the left of a US style "liberal", that is equally offensive and racist as only generating white people. Injecting fake diversity into situations where it is historically inaccurate is just as big a problem as erasing diversity where it exists. The Nazi example is stark, and perhaps too stark, in that spreading fake notions of what they look like seems ridiculous now, but there are more borderlin…
I think you hit on an another important issue: Do people want the generated images to be representative, or aspirational?
E.g. let's say you're making something about a population with 5% black people, and you're presenting a group of 8. You could justify making that group entirely white very easily - you've just rounded down, and plenty of groups of 8 within a population like that will be all white (and some will be all black). But you're presenting a narrow slice of an experience of that society, and not including a single black person without reason makes it easy to create an impression of that population as entirely white.
But it also needs to at scale be representative within plausible limits, or it just gets insultingly dumb or even outright racist, just against a different set of people.