That's a great point, as long as it works it doesn't matter where it came from.  The basic idea behind what their trying to build has been floating around for some time, earliest I had heard it discussed was cloakcoin, but it's likely the idea was around before that.  The plan is simple; build an anonymous currency, and with a decentralized market to prevent government shut downs and exit scams, you have the first real successor to the silk road, and a platform that could see some serious cash flow (it's estimated that over a billion in USD went through the Silk Road).

It's such a good idea, that it has been used by as least 5 different scams that I can name off the top of my head; Cloak, Razor, Stealthcoin, Sling, and Crave, all of these playing off of the same promise of a decentralized anonymous market.

Personally, I think it's more of "when" rather than "if" something like this is made, and if you spot it early, you've found a gold mine so to speak.

For now I am leaning towards cautious optimism about the Shadow Project (have been for a while).  But for anyone that doubts the project, the question you should be asking is "if not Shadow, then who?",  the potential for a project like this is too great for me to believe that no one is actively pursuing it.  There are other projects focused on improving anonymity, and there are projects that are working on decentralized markets, but to the best of my knowledge no other project is attempting to do both, and to be honest I find that somewhat perplexing.