I doubt I can give you a proof of failure that you ask, and I'm not 100% solid or professional on financial terms, but I think my questions maybe worthy and helpful (let me know if they are not).

1) Currency=Shares=BitShares, right? Share dividends and mining fees are paid in what, fractions of shares? Rewards are shares, the native currency of this chain, right?

2) So if I have 1 Bitshare, I can issue any type or amount of sub-currency by backing it with either my own share, or the future dividends from it?

3) Trade of BitShares is possible, right?

4) Why bother issuing sub-currencies, what does that help or solve? Why would I give someone my real gold for a crypto-gold that is backed by someone's BitShares/dividends, which is backed by bitcoins, which is referenced in exchange rates between paper monies? Wouldn't I rather opt for for the BitShares themselves?

5) Is the interest rate determined by the user, or the mining fees/rewards/transaction rate? Are dividends always half? Are interest rates and dividends separate?