The black swan big disasters have to be taken seriously too.
A nuclear accident creates a big and costly disaster suddenly. People don't like sudden big problems but can live with continuously growing ones.
Burning hydrocarbons is much more acceptable in that regard. CO2/dust pollution is accepted by society, because it is continuous and dilutes well. Killing millions is socially acceptable when it happens randomly all over the planet. Radioactive pollution due to coal burning is/should be negligible, most is(should be) filtered out in the smokestack scrubbers.
I don't like fossil power plants, but they are much easier to build and more acceptable to people than nuclear ones. That's why regulation and security have to be high with nuclear, to make it acceptable to most of society.
> civilization-ending danger
I don't think climate change is a civilization-ending danger in the coming decades. It already creates political problems, migration. If we keep pumping CO2 then maybe in hundred years.