However, the important point is that if you ask, in a polite, reasonable, and upfront manner, for a scientific assessment of cryonics and what exactly are the problems with it, it is not possible to get a full, honest, and scientifically sound answer, as demonstrated by that article to which I linked above. Contrast this with what happens if you ask, say, physicists what is wrong with some crackpot theory of physics -- they will spell out a detailed argument showing what exactly is wrong, and they will be able to answer any further questions you might have and fully clarify any confusion, as long as you're not being impervious to argument.

I think most parties involved agree that cryonic revival is a bit of long shot. It is hard to say exactly how much of a long shot it is - since that depends on speculative far-future things like whether an advanced civilization will be sufficiently interested enough in us to revive us. Scientists can't say too much about that - except that there are quite a few unknown unknowns - and so to have wide confidence intervals.