This came from a failure to distinguish between alienated and social labour. Communists and devout Christians shared the contradictory belief that although rejection of unnecessary private property is good for the soul, in practice it is an act of self-denial. Such contradictions could, and perhaps would, have been resolved had the party education system been geared to free discussion rather than being wedded to the Soviet catechism. Just as, for some reason inexplicable to us, the Roman Church sponsored the Greek model of the universe against Galileo, so Communist parties worldwide pushed a centuries-old Newtonian model at a time when quantum theory had been accepted for ages. What relation mechanistic views of science had to socialism was never made clear.
Feminists know better.
Why they failed Revolutionary spirit arises from the contrast between what we experience in the here and now and what future we think is possible. The utopias we believe in need not be feasible as long as they are attractive. To be attractive, models must address the needs society fails to fulfil. In the '30s it was attractive because it was remote and its rhetoric reflected the aspirations of ordinary people in the grip of depression. Once the phoney war had ended, the exploits of the Red Army in its fight against fascism gripped the people's minds.