Yglesias ponders it:
A lot of the issues around autonomous cars amount to basically "but under some conditions something could go wrong and cars could crash and people die." Meanwhile, over ninety Americans die each and every day thanks to automobile mishaps, and 1.2 million are seriously injured every year. There's a social convention in the United States that we don't talk about those ninety daily deaths as a serious problem, even though obviously if we had nine people getting killed by terrorists every month there'd be a perpetual state of freaking out. High-speed motorized transportation is a serious business, and conventional automobiles are held not to the same tough safety standards that we apply to most other products so it's extremely difficult for something new to compete.
The Dish 