If your vehicle is heading relentlessly toward a group of schoolchildren it would be nice to have a way to override it. Either that or no windows so you won't be haunted by it every night of your life.
I'm not sure if I'm optimistic about autonomous vehicles or just very pessimistic about human drivers. I have no confidence that the next driver making a left turn while I'm crossing the road won't kill me. I'm much more comfortable with a computer that is programmed to avoid killing me, even if the software may have the occasional bug, than with a human who may or may not prioritize my life over whatever else it is…
I think the real concern that the car is actually programmed explicitly to kill you if it has to, to ensure it's own safety or the safety of it's riders or something.