Actually. Good you mentioned Steemit. Because, while I have problems with the blockchain STEEM doing savings/loans, I'd have zero problems with a Steem-backed -UI (e.g. Steemit, Busy, chainbb, dtube, dsound, zappl) doing exactly this; allowing their users to Save their STEEM in exchange for intereste. Effectively, investing this money into whatever the maker of that UI decided. I think some SMTs will end up running this kind of model in their communities.