Sure. For one, with a short life expectancy you're not being detained where you live. [... stuff about suicide ...]

Okay, I think I'm convinced about that part (partly by what you wrote and partly by realizing that some problems with suicide tourism I was thinking about seem exaggerated after thinking them through).

Unfortunately, this made me realize that this point wasn't really relevant to our disagreement. I still don't think that lack of cryonics-related suicide discourse on the Internet indicates that cryonicists' don't expect cryonics to work (or even that cryonicists' aren't privately considering the possibility of assisted suicide), so it was a bit disingenuous of me to bring it up. Sorry about that.

Upon further reflection I realized that I don't really even care whether people are using cryonics purely as an existential terror management strategy. I don't consider 'look at all those people who already signed up' to be a very important (or even valid) argument for cryonics so even if some of those people turn out to be totally crazy, it won't affect my belief in the possibility of cryonics working. I think my real beef with your post was abusing the concept of belief-in-belief.

Which you're still doing, by the way.

The actual merit of the preservation approach nonwithstanding, how is cryonics not the technological equivalent of a deep-frozen stairway to heaven? The parallels in terms of eschatological topics (including skipping death, chance of skipping ahead in limbo to some kind of death-less future) are easy enough to find.

Maybe. But a very important difference that makes the belief-in-belief concept inapplicable here is that no one claims that believing in cryonics (unlike believing in gods) will by itself affect reality in any way. Believing in cryonics isn't considered important.

If someone takes genuine comfort from the fact that they're signed up, then I'd say that they really believe that cryonics will work. Maybe they started believing it only for this comfort without really thinking rationally. Maybe they believe it too strongly. Maybe they got carried away and convinced themselves that the magical cryonics fairy will take care of everything and they don't have to worry about unpleasant technical details like ischemic damage caused by delayed suspension. But it's not belief in belief if they are actually willing to spend a pile of money on it. (In case of religious activities people can also spend money because of signaling without really believing but right now spending money on cryonics mostly gets you scorn and ridicule so that hypothesis is out.)

It seems to fit the kind of reasoning arguing for the invisible dragon pretty nicely.

Ah, but people are actually paying to have their garages suffused with dragon-killing chemical agents (dracocides?) And you're saying that they don't really believe in the dragon?

(Excuse the tone, no adversity intended. Also, minor typographical edit)

No need to excuse anything, I haven't registered any adversity.