Yes, whereas massive numbers of computers are hacked all the time, causing all sorts of issues. Instead of one human going nuts and causing an accident, we'll have dozens, hundreds, or thousands of compromised or badly programmed cars killing many times more people. If we can't even guarantee security of our currently networked devices, then it's only a matter of time before these cars are hacked through the wireless mesh. They will be very tempting targets.
Assuming you're doing what you're supposed to behind the wheel, you're watching the cars around you as well as your environment. You see that truck with the loose cargo that looks unbalanced? That object in the road, is it a plastic bag or a rock? You see a car two cars in front and one lane to your right.. By the type of car, it's behavior over the last 2 miles, and its condition, you know there's a high probability of erratic or aggressive driving. You know to watch that one. Good luck programming a computer with this. Humans are slower and less predictable, but they are much more aware of details in their environment and this more than makes up for those weaknesses. A computer is just a state machine programmed by someone else making assumptions and using heuristics to guess which situation the car is in atm. Google gave a talk about their system, and it works just like that.
A proper human driver is miles ahead of any computer. If the problem is inattentive driving, then the answer is to fix that, not to encourage more dependence and laziness.