I've noticed too that most people assume they are better at things then they actually are - not just with driving but in general. There are very few people who can actually multitask, but the majority assume that they are one of those few (even when presented with evidence to the contrary).
Many people swear that talking/texting/browsing/whatever on their phone does not inhibit their driving abilities. The reality is that there is maybe 1 person in 1,000 who is capable of doing so, but that one person is typically smart enough not to do it.
Unfortunately, perception is reality. People's perceptions are that humans are awesome and the best equipped to respond in some hypothetical unknown situation. This clouds people's reception of a computer, which is capable of processing and reacting far faster than a human, that is capable of handling day to day driving.
Are there situations where a computer can't figure out what to do? Certainly, and that's when a human would be needed. But in this case a computer controlled car would pull safely off the road, and alert the driver to take over. Mesh the cars, and eventually all the cars learn how to deal with this aberrant situation.
~shrug~ But I'm an optimist that hates driving. I'm ready to stop.