I wanted to have an electric car since I graduated from college in 1998. I remember arguing with my family then how an electric car was better primarily because it moved the source of pollution from non-point source to point source.
It is very difficult to control non-point sources of pollution (everyone who has a car) as there are too many dispersed sources. Point source pollution is easier to control because there are far fewer concentrated sources (think of a power plant), Electric cars provide a simple method to easier monitor and control vehicle emissions.