1. They want to say something about themselves. This is the Leonardo DiCaprio buyer, using the electric car to pronounce that he cares about his carbon footprint. And it looks great parked next to his Gulfstream V.
2. There is no meter on the electric line you plug into the car. When you fill your car up with gas, you get to stand there watching the spinning money dial. There is no parallel experience for plugging in an electric car. The costs and fossil fuel use of an electric car are not necessarily less than the same size (e.g. subcompact) gasoline-engine car, they are just better hidden.
Owners of electric cars are not smarter about managing the energy costs of their driving, they are substantially more ignorant. I know exactly how many dollars of gas I have put in my car this month. How many electric car owners have the first idea how many dollars of electricity they put in theirs?