There should be at least three reasons for EV:
Firstly, decrease pollution! EV as a zero-emission-car can help improve the environment a lot;
Secondly, decrease the cost! Though the initial buy cost of EV is higher than gasoline car, the maintainance cost of EV will be extremely lower than gasoline car. Based on calculation, for a 48V EV, it only consumes 2KWH electricity per 100kms. Cost is much lower than gasoline car.
Thirdly, energy independent! For a country who is lack of oil source, it should find a way to make itself independent from oil. Water resource, sun resource and wind resource are potential alternative resource, the problem is to find a medium to storage the engery. Then battery will be the best choice at this moment.