> Because if they're needed, they're not sustainable

You can pack enough to survive for decades in that bunker, and then see how world will look like. If you are superrich, it is dumb to not take this chance.

> Maybe these sociopaths should try to save the world rather than making fantasy hedges against its collapse (while actively making things worse).

Its very loaded topic. There are other competing sociopaths, and also 8B of population who don't care about saving world much. But both goals(bunker and saving the world) could be tried simultaniously.