Because they are "electric"...where are you going to get all of that electricity?....sun?...wind?...think again....it comes from oil and coal....electric cars are as polluting as combustion engines....until we can produce super fast charging solar panels that will charge on cloudy days with small easy to handle batteries that will hold an unlimited amount of power and charge quickly we are not going to move away from oil in any significant way....I'm not saying we shouldn't try and keep working on it...but we are just not there yet....anyone with solar on the roof of their home or RV will tell you the same thing....