... if people don't believe that the science benefits of these missions justify the development of the technology.

That isn't being Luddite - critics of space nukes aren't calling for bans on space exploration - but a different assessment of what the costs & benefits are. Many critics of the technology grant the need (if not willingly support) the use of small radioisotope sources for power for some particularly solar challenged targets (as on New Horizons); but with solar powered instrumentation (as opposed to propulsion) already feasible at Jovian distances, few if anyone would support reactors being flown to get to a particularly difficult space science target a little quicker... especially when there are so many cheap nonnuclear missions waiting to be flown.

A reality check is definitely in order here....

Robert