What are you talking about ? where on the BitcoinOPX or MPeX I can buy apple stocks of some other stock traded on NASDAQ?
What BitcoinOPX and MPeX doing is apply old tools for new currency I more in the Idea of attract fiat money to bitcoin economy and never go back.
I thought you were talking about a synthetic? (which, of course, is not buying AAPL it is an artificial product that has nothing to do with AAPL except simulating its price moves).
BitcoinOPX has options, including for AAPL. There is a pull-down select box. Select AAPL for AAPL options.
As far as how one would attract investment this way, I don't know. It is a difficult problem because presumably you are operating this anonymously and thus it is easy to con investors. And if you aren't operating it anonymously it is vulnerable to confiscation by regulators.