In fairness, humans have a lot more than just optical sensors at their disposal, and are pretty terrible drivers. We've added all kinds of safety features to cars and roads to try to compensate for their weaknesses, and it certainly helps, but they still make mistakes with alarming regularity, and they crash all the time.
When you have a human driver, conversations about safety and sensor information seem so straightforward. The idea of a car maker saving a buck by foregoing some tool or technology at the expense of safety is largely a non-starter.
What's weird is, with a computer driver, (which has unique advantages and disadvantages as compared to a human driver) the conversation is somehow entirely different.
