Here is another idea that might be argued to be anti-cryonics. Should we clone Neanderthals?

Bernard Rollin, a bioethicist and professor of philosophy at Colorado State University, doesn't believe that creating a Neanderthal clone would be an ethical problem in and of itself. The problem lies in how that individual would be treated by others. "I don't think it is fair to put people...into a circumstance where they are going to be mocked and possibly feared," he says, "and this is equally important, it's not going to have a peer group. Given that humans are at some level social beings, it would be grossly unfair." The sentiment was echoed by Stringer, "You would be bringing this Neanderthal back into a world it did not belong to....It doesn't have its home environment anymore."

There were no cities when the Neanderthals went extinct, and at their population's peak there may have only been 10,000 of them spread across Europe. A cloned Neanderthal might be missing the genetic adaptations we have evolved to cope with the world's greater population density, whatever those adaptations might be. But, not everyone agrees that Neanderthals were so different from modern humans that they would automatically be shunned as outcasts.