It's clear at this point that your opinion is not as extreme as I the impression I originally got (unlike some people) and I don't really disagree much with what you say here. I too am skeptical of current methods (and I'm not signed up for this and other reasons), but I'd like to see further work on both traditional cyropreservation and other methods such as plastination, taking into account any new research on memory formation and storage. The idea being to get to a point where we can preserve an animal brain and check to see that the important information seems to be preserved (even if we can't read it back out yet).
In the past, the Cryonics Institute has had a policy that said that they would not accept anyone who is not a member. This has changed. The policy now is that someone who has full legal authority over your body can sign you up after you die. It costs $36,250 to be frozen if you are not signed up, which is more expensive. They also will not do anything until you have been on dry ice for 2 weeks after they have been contacted, so not being a member is more risky.
This is very important news for anyone who is currently cryocrastinating. It means that you can drastically increase your chances of survival without filling out any forms. All you have to do is tell a loved one you want to be frozen upon death, and that you would like them to take responsibility for making sure this happens. This takes literally 30 seconds. Do it now!
This news might also be a reason to not sign up right away, if you think something better (like radical life extension or uploading) will come along in your lifetime. We should discuss this in the comments.
Edit: The general consensus of this discussion is that this is a really bad reason not to sign up for cryonics.