I guess you don't like the idea that Bitcoin savings can be more profitable than saving your money in a bank.
If the saving account was guaranteed by a contract, yes. However that is not what happens with BTC. Anyone holding BTC do not have any guarantee to receive interest over the amount hold. BTC holders rely on a forever optimistic market to increase their capital.
Think about my idea. Perhaps a company could create their own electronic cash (Airportcoins?) and use as unit of account to keep track of the deposited loose change. Them they could use that electronic cash to speculate in the exchange markets. That would be possible because there would be always people depositing loose change here and there around the world. People would only redeem the amount deposited after some time, providing the company with funds enough to leverage in the exchange markets. That could generate a margin of profit to allow the company pay back the same amount deposited by a customer.