Owner that saw the lag in the menus and games. And a lack of games. The majority of them are ports like final fantasy 3. Meaning there is no reason to get one since the majority of the games are available on mobile devices. Then some of them realized they threw money into the kickstarter project of the ouya for nothing.
I'd agree with TechFreak, it is most likely so low because most people are getting by using it as a streaming device and free game trials.
I can't find specifics but I've heard in the past that most people on Android have never paid for an app...and that over half the apps in the marketplace are free anyway.