Is it really even as remotely likely that religious fanatics will take over and then do that as it is that cryonics would work?
In my opinion, no. But the argument I was addressing seemed to be that one should do cryonics, even if the odds of it working are tiny.
Yes, because there are positive arguments for cryonics working and not having negative effects besides the well-known ones. Fantasizing about religious fanatics taking over during your lifetime is about as sensible as fantasizing about another group of fanatics taking over and cutting off healthcare to everyone who didn't signup on the grounds that their revealed preference is to die sooner. (Notice the isomorphism here to issues with Pascal's Wager and the 'atheist's god'.)
From Mike Darwn's Chronopause, an essay titled "Would You Like Another Plate of This?", discussing people's attitudes to life:
Conclusion, graphs, and references in article. As usual, I recommend reading Chronopause.com as Darwin has many good articles; to quickly link a few: