Obviously people believe that autopilot represents a net benefit to air travel, but there are far fewer planes in the sky than cars on the road, a lot more open space that is not impregnable by most foreign objects, and a ton more money per plane allowing for more sophisticated sensors and systems. There is a dedicated traffic coordination system for aircraft and each pilot takes instruction as given by the ATC. Planes are also constantly monitored by highly-trained pilots and mechanics and operations are closely supervised by multiple regulatory bodies.

A great deal of the required operations for autodriving are offloaded or irrelevant in autopiloting. I know we were talking about an isolated case of the unexpected failure of an automated piloting system, but if we consider all of these additional complexities in typical road driving * millions more cars with barely-trained operators, it's reasonable to suppose that those types of problems would occur much more frequently with autodrivers than autopilots.