I was an original backer for the Ouya. The interface is a bit awkward, but worse, the software titles just aren't compelling. There doesn't seem to be a great reason to make an exclusive Ouya game, and anything you can find there you can get on your phone or another platform. Playing smartphone games on your TV just doesn't deliver any kind of wow factor.
Non-compelling titles and not much reason for developers to target the Ouya platform pretty much sums it up. Also, for all the hype concerning the controller, it's not very well-designed and the buttons stick.
I'm still rooting for them, but the execution was pretty disappointing.