Most physicists do not think it works.
This claim would require citation and such a citation does not exist. Most physicists have not thought about the subject one way or the other. Moreover, most physicists (those who don't have particular expertise in information theory) are not particularly qualified to evaluate the subject except, of course, as intelligent laymen.
Most neuroscientists do not think it works.
It is possible to find neuroscientists who are not aware of their own incompetence outside their area of expertise and who claim that cryonics cannot work. All such 'expert' testimony that is dragged up here over and over has included claiming that cryonics cannot work because it is not possible to repair preserved neurons in place. Since this is not remotely how cryonics works whatever dubious claims to authority that they may have had are screened off.
The private_messaging account is one of the many identified sockpuppets of a persistent troll. Me choosing to reply to it constitutes feeding a troll---it is deeply disappointing that voting standards make it necessary. Nothing said to it will influence its behaviour except by virtue of providing more information about typical beliefs so that it can better target its provocation.
Most physicists have not thought about the subject one way or the other.
I would assume most physicists hold the standard pop-culture position, actually, just like anyone else.
However, the rest of your comment is entirely correct, including the disappointing karma result; I personally didn't downvote them, but only because my karma is being periosidally mass-reduced by someone whenever I get close to passing the limit that would exempt me from the anti-troll restrictions :/
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.