"The launch of the world’s first mass-producible driverless car is a major accomplishment, but we’re not across the finish line yet. Building a few of these self-driving vehicles, or even a few hundred, won’t accomplish what we set out to do. And a self-driving business that depends on humans sitting behind the wheel is fundamentally unsustainable, so that won’t cut it either. We will achieve success by integrating the best software and hardware to deploy truly driverless vehicles at scale."

That's the last paragraph. It makes me think the writer views it as a technical problem - they need a human as a backup. But, there's not enough context, so I could be misreading it.