> I think it's very unlikely that this company will be able to keep the bodies preserved until we develop the technology to revive them.

"Very unlikely" seems too pessimistic. Alcor is almost half a century old, and their finances and governance are more secure than ever.

> I also think it's unlikely that a future society will allocate resources to revive these people, even if we suppose technology exists and the bodies are well preserved enough.

The brains aren't tossed into a freezer and forgotten. Alcor uses interest from a trust fund to pay for maintenance (mostly topping-off the LN2). Likewise it would probably be Alcor (or some organization paid by them) doing the reviving.

> Everyone who knows these people today will surely be dead by that point.

Hospitals work despite the fact that the staff don't personally know patients. Even so, Alcor's Patient Care Trust Board is required to have a majority with relatives or significant others currently in cryopreservation.[1] The incentives are aligned as closely as possible. (I wish people would look this stuff up instead of making false assumptions. Alcor isn't run by fools. They've built an organization that is resistant to the commonly-conceived failure modes of cryonics.)

There are other incentives to revive people: If historians could resurrect some people from the 1800's, they'd probably try. Another possibility is that some person or organization wants to show off their technical prowess. And don't forget general altruism. A world in which revival is possible -but doesn't happen- is one where everyone in the world decides against investing resources. It also requires they all stick with this decision as the cost of revival decreases over time. That seems incredibly unlikely to me.

> Furthermore, many of the people paying for this seem to believe in the inevitable emergence of a utopian society with unlimited resources, which seems almost a necessary condition for these people to be revived. Personally, I'm not banking on that happening either.

Compared to 150 years ago, we are a society with absurd resources. The world economy has grown 100x. More people die from obesity than starvation. In developed countries, sick people are transported to hospitals where diagnostics can include injecting them with gadolinium and shoving them inside a superconducting magnet. If rates of economic and technological progress continue, we'll scarcely be able to imagine the wealth and abilities of our descendants.

Please note that all of your arguments against cryonics involve complications that make it less likely, not show-stopping issues that make it borderline-impossible. Most who are signed up for cryonics think it probably won't work. But if a doctor says, "You have cancer. Your only hope is an experimental treatment.", I doubt you'll reply, "There's a good chance it won't work? Nevermind."

If you're like most people, you'll consider the costs and possible outcomes. Maybe the treatment is expensive, painful, and incredibly unlikely to work. In that case, it makes sense to skip it and leave your family with more money after you're gone. Or maybe it's cheap, painless, and has a 5% chance of success. In that case, it's worth a shot. Depending on your estimates, cryonics can fall into either camp. But it's important to actually do the expected value calculation instead of reflexively objecting to it.

1. https://www.alcor.org/AboutAlcor/patientcaretrustfund.html