That's a proof their system was a lie. Che Guevara gave an speech about how Cuba would thrive without global trading, without private property. Well, the results speak for themselves. No communist regime could survive with its own production. It seems i triggered some communism fans.
So far as I can tell it's this way because 95% of the US doesn't care one way or the other but there are Cuban exiles in Florida who care a lot about punishing Castro, and they're good at voting.