They're quite up front about the fact that they have no idea how to bring anyone back. People choose to get cryo-preserved despite that because, as far as some people see it, it beats being buried underground or burned to ash.

Marvin Minsky who passed away recently was on the board of Alcor (one of the main cryonics companies in the US). Does he seem like a scammer to you?

Please research your claims before accusing people of "scams" left and right.