Mostly public perception (annoyingly): people are still going to have a go at being anti-nuclear about it, but building a fusion power reactor is going to have a lot more public cultural cachet to draw upon then fission. We've got a generation of science fiction who's core message is "fusion power solved all the problems".

Though there are genuine advantages: for as radioactive as the interior of a fusion reactor may get, if you cut power it'll just sit there safely doing nothing. No decay heat, no potential isotopes to leak - maybe a puff of tritium gas - but that's it. It is a technology that has a perfect control loop for safety because it can't self-sustain at all.

Thanks for the explanation.

I think there should be a bigger effort to change public perception about nuclear fission reactors if we're on the cusp of what is effectively the equivalent of the dream of endless fusion energy in the latest generation fission breeder reactors.

Contolled fusion may give way to real alchemy (think synthesising water and steel just from hydrogen atoms).