This blaming the environmentalists for nuclear's failures is quite a tired argument. In addition to being false (environmentalists didn't have the political capital for it in the critical decades) the enormous public subsidies towards nuclear power in the past 80 years were an opportunity cost away from renewables. If we had spent even a small part of that on renewables r&d investment starting in the same timeframe (40s/50s) we could have transitioned from fossil fuels decades earlier.