This is a valid critique, but only if you were using the SATSCARD like a cold wallet. It is intended to act more similarly to cash that gets exchanged multiple times before being unsealed and the contents of the wallet sent to a different address.
You are correct that right now the usecases are not terribly high, since it becomes a very ineffecient cold wallet like you said. But it is awesome that Coinkite is building on and working with the idea of giving bitcoin a physical cash form, since that could be extremely useful when Bitcoin becomes mainstream.