Many modern cars already have so many different things going on in the background that they're half driven by wire anyway. Taking this to the next step where you tell the car where to drive is progress and would likely result in many fewer dying in accidents.
Power tools are actually a great example of dumbing down things for safety's sake. The $20 drill you get at home depot that can barely go through an Ikea table isn't what people that make buildings for a living use and will do far less damage to you if your hand slips. More importantly, there are no metaphors to get with a drill. You point it at something, pull the trigger and it drills. People still manage to injure themselves on accident, as they are human. Ideally the drill would be able to look at where it's pointed at and *stop drilling* if it's looking at flesh.
Even airplanes are a great example. I have no idea how to fly a plane, but there is someone that can get paid a great deal of money to fly for me. All I have to do is figure out how to buy the damn tickets from a website somewhere (which could be made easier, really). And even pilots aren't controlling every element of the plane without assistance from a variety of computers.
Most people that use computers on a daily basis aren't computer experts. They're engineers, architects, scientists, lawyers, businesspeople, personal assistants, etc. The computers they use are tools to accomplish something. Some people get it, others don't. But forcing people to use metaphor after metaphor that has nothing to do with their jobs frequently doesn't result in someone that knows what the metaphors mean or how they interact, it simply results in someone that knows how to keep clicking a certain way until the black box gives them something the way it did in the past (at least until they upgraded it and everything moved around to make it more user friendly).