An authority figure in the cryonics movement will finally acknowledge that Drexler's "nanotechnology" simply can never exist because it gets the physics wrong.

Please provide an explanation or citation. In the mean time, here is a growing list of peer-reviewed publications of ab-initio quantum simulations of Drexler-esque diamondoid mechanosynthesis:

http://www.molecularassembler.com/Nanofactory/Publications.htm