The reason for the disparity here is because, while you're right that humans are not particularly good drivers, there is a massive institutional infrastructure

The reason for the disparity here is because, while you're right that humans are not particularly good drivers, there is a massive institutional infrastructure built up around things like criminal prosecution and insurance for when a human messes up. We know[0] how to deal with (accidental or deliberate) 'bad' people. We haven't quite figured out how to do that with intelligent systems that blur the line between automatic and intentional. --- [0] Of course, there is much valid debate as to whether we really -know- how to do this either. But legacy and history carry weight, unfortunately, either way