One way to fight this is to reframe cryonics as similar to CPR: you'll still die eventually, but this is just a way of living a little longer. But people seem to find it emotionally different, perhaps because of the time delay, or the uncertainty.

That's more comparable to being in a long coma with some uncertain possibility of waking up from it, so perhaps it could be reframed along those lines; some people probably do specify that they should be taken off of life support if they are found comatose, but to choose to be kept alive is not socially disapproved of, as far as I know.