Just speaking as OP, I think it's bc of the little information that gets into the public about nuclear science in general, much of it is about the cost and dangers of nuclear waste. I have the impression of this thing that has to be maintained by burying it under a mountain in North Dakota for the next 50,000 years.

So while 5 orders of magnitude makes the financial case clear, I don't have a good idea if the risks of keeping it around are potentially 6-7 orders of magnitude greater than getting rid of it.