Machines will be (and already are) held to a much higher standard than human drivers— there are a lot of reasons for this, ranging from the emotional to the pragmatic.
Just because thousands of people roll the dice every day driving in unsafe conditions does not mean that we should tolerate machines doing so.
One note is that perhaps people roll the dice because they want to feel some control and forward momentum. But if you're sitting in the car, being autonomously driven somewhere will you be so impatient?
I assume the car will give you an ETA, so you'll check the clock and go back to your book/social media. I'm okay with "slower, but smoother".
Just because thousands of people roll the dice every day driving in unsafe conditions does not mean that we should tolerate machines doing so.