Why are people against energy sources other than fossil fuels?

A significant amount of power in my area comes from the hydro plant, and the dam has capacity to generate much more, they just don't function at full level because theyre mostly just there to back up the coal plants instead of being the primary power source.

I don't even care about climate change or whatever, it's just the idea of tying your national infrastructure to a finite resource, especially if you live in a country where it has to be imported instead of having domestic production.

I also don't understand why a lot of people scared about climate change and against fossil fuels are also afraid of nuclear power, which is clean, reliable and long lasting.