Nuclear had many decades in which its cost could drop. That failed to happen. Unlike with renewables, nuclear never had relentless cost decline. Its learning curve has even shown negative learning, with costs rising with time rather than falling. There's something about nuclear that just keeps it from getting cheaper. The scale and complexity of nuclear plants probably has something to do with it, and also the maturity of the non-nuclear side.
Fear mongering must be incredibly powerful, if it has universally stopped nuclear from getting much (or at all) cheaper, everywhere in the world, in multiple cultures.
Much more plausibly, the technology itself is to blame.
