Tesla and other self-driving developers are working without the luxury of a worldwide mapping database, and while not perfect, their products more or less could work on any road, because they're based on input from the sensors. But Google cars are dependent on input from Google servers, which means, where that data is lacking, the cars can't drive.
If they're looking to run some sort of business to start making money, I could maybe see like an Uber-like service across very small geographic areas they have mapped. But the narrow fence around the area you can practically drive with one makes it useless to sell as a consumer vehicle.