I like my Ouya... he says, sheepishly.
Yes, you still need a credit card or a prepaid Ouya card to complete the setup, much like you need a credit card or a prepaid Google Play card when you want to get things on your Android device from the Play store. Ouya cards are sold at Target stores in the US (I don't know about countries outside the US, so I'm sorry if that doesn't apply to you). That said, you could get a prepaid MasterCard or Visa at your local convenience store and use that to set it up if you feel uncomfortable with using your personal card.
Ouya's current selection has grown to well over 1000 games and apps in their store, some even being made by well-known developers (JackBox, Farsight, Square Enix, etc.). The OS has been updated numerous times since you last turned on your system, so there are improvements overall. If your system is just "collecting dust," I suggest you find someone else to give/sell it to who will at least find some enjoyment from it instead of it being a source of irritation.
All that being said, I really like my Ouya a great deal. It just fits my style as a casual gamer who doesn't need the latest and greatest. For that matter, a friend of mine got one of his own after playing around with mine, so there's that.
Wait... someone who actually LIKES the Ouya?? He must be a troll! Let the downvoting commence!