We don't need to explain why this trend doesn't apply to cryonics. The complaint is not with the trend, it is with using "future technology" as an answer to specific problems we do not know how to solve. Its not an answer at all, its like saying "we will solve it by solving it...later".
"we will solve it by solving it...later".
For values of "later" around the 20 or 30 year mark, this is not a very convincing point. But for values of "later" in the hundreds or thousands of years, it has some weight.
Luke Parrish points me to what is clearly by far the most serious critique of cryonics ever written: a 57-page treatment by Evelina Martinenaite and Juliette Tavenier, presented as a 3rd semester project at Roskilde University in Denmark supervised by Ole Andersen.
Full paper