Nukes were to prove to have the big problem that the radioactivity corroded the equipment making it easier to behave less than perfectly.
If someone has come up with a better solution to the problem of failing, which not a whether question but a when question, it deserves respect. If it is expected to melt down upon failure, and it is designed to catch the meltdown if it does, then we have a promising design. Don’t try to evade the failure mode; instead harness it.