That period in the US in which we recoiled was made possible by the horrors so many had lived through, a sane response to an insane time. It was an opportunity that was grasped for only a few years, however. 1945–55, perhaps. Progress continued for a time, and the echoes of that first burst had long-term positive effects.
But the other half of the response was to cocoon ourselves, victims of a stress disorder, from the thought of it happening again. The peace we made for our (white) selves in the post-war years was partially illusion, born of the shock of horror.
Few of us now know this horror today. That is, as you say, part of the problem.
Very provocative and well-written. Hope to see more from you.