If you can make a car that would drive significantly better then a human (accidents per mile) why wouldn't you?
Because people are irrational. We fear exotic deaths more than we do mundane deaths. Travel by airliner is much safer than travel by car, yet every time there's a plane crash we have a huge investigation for the purpose of figuring out what went wrong so we can prevent it from happening again. But tens of thousands of people die in car accidents, and all they get is a brief police report stating it was an accident without really delving into the cause. Why? Because death by airplane crash is more exotic than death by car crash. The same thing plagues nuclear power. Death by radiation is exotic, death by falling or getting lung cancer from soot inhalation is not. So we scrutinize and heavily regulate everything to do with nuclear power when it's already the safest power source we've ever invented in deaths per MWh of power generated, while turning a blind eye to deaths by coal (pollution), wind, and solar (primarily falls during maintenance - their diffuse nature means there's a lot more maintenance to do).
You double down on this if the accident was in your control vs out of your control. If you could've done something to prevent the accident (was driving a car) but failed to so, you say "Oopsie, I won't make that mistake again. No give me my keys back." If someone else could've done something to prevent the accident (driving a bus or piloting a plane) but failed to do so, you sue the bastard for everything he's got and try to get him banned so he never drives/flies again.
The combination of these two means autonomous cars have to become a helluva lot better than human drivers before they'll be accepted. Dying because of a typo in a line of code counts as really exotic, and the press will have a field day with it the first time it happens. And the makers of the autonomous cars will need huge insurance policies to deal with the extra liability they'll incur, since it'll likely be bigger than the sum total of all private auto liability insurance policies today (a few percent of the purchase price of the vehicle every year it's in operation).