[hchz]

These examples provide your answer - digging just past the surface, they're not better at giving people what they want.

The vaneless ion generator is >5x less efficient.

Molten Salt Reactors, on the surface, sound quite safe, but nuclear power's primary problem is economics, and this is an unproven technology operating over the long time scales needed to amortize reactor construction costs. Nuclear power systems present novel failure mechanisms that don't exist in everyday technology, such as the corrosion mechanisms caused by coupling of mechanical, thermal, chemical, and radiological stresses, and MSR's present a new set of these that are poorly understood. Additionally, MSR's exhibit thermal shocks in normal operations orders of magnitude above what may be produced in a water-cooled reactor.

It's just not that simple - it looks simple to you.

[Joker_vD]

And yet the molten-sodium and molten-lead reactors, which sound quite unsafe, actually exist and used even today, since the seventies, actually.

[hchz]

Yes, they actually exist in the West as research reactors, since there has been no demonstration or certification of their suitability for long-term operation.

[carapace]

It seems to me like you're just being circular now, like you're saying "Sure, MS reactors exist, but we don't know if they are good because we haven't done the work to find out."

Going back to the original article "Why isn't differential dataflow more popular?" we could ask "Why aren't Molten Salt reactors more popular?"