Careful, someone else just gave me the "dumb question" lecture.
Yeah, I saw that, and thought it was unjustified.
Anyway, I can see where "it's our job" angle is just as good an answer to "why won't you ditch the body first chance you get?" as it is to "why won't you just store the body indefinitely rather than revive it?"
And I can see where it isn't a very confidence-inspiring answer, as you say.
That said, I'm not sure there's a better answer to be had. We do all kinds of things that depend on the assumption that legal and financial arrangements will remain more or less as they are; signing up for cryonics is no less justified on that basis than setting up a trust fund for my grandchildren.
For alcor atleast, the people in charge of the money are REQUIRED to be signed up for cryonics and I believe 3 of them need to have close relatives or significant others already in cryonics. This means that's it's in the interest of the people in charge to not screw themselves or the people they love, instead of not screwing random frozen strangers.
So, apparently appsumo is having a custom reddit bundle, a bundle meant to appeal to redditors, and 10% of the proceeds get donated. On the surface, doesn't sound _that_ interesting, except...
Take a closer look: http://appsumo.com/reddit-special-deal/ and find that the recipient of the donations will be... SENS!
I find this to be an interesting development. It wasn't the "custom transhumanist bundle" or "the custom sens bundle" but "the custom reddit bundle". Yes, "reddit" doesn't, in and of itself, count as extremely mainstream as such, but I'd say it's still an interesting development.