The computer explosion happened not because of computers per-se but because of the internet. Email and the web, and later Facebook, Twitter, etc. made computers able to do useful things. If that had never happened, the majority of the public would have little use for computers.

So you're right, the electric car will become practical for people not because of any capability of the car itself, they are already more than adequate in that regard. It's the batteries. When we have some way to get similar range and speed and ease of recharging as pumping 10 or 20 gallons of gasoline, they will be practical for most people. Not really before and until that happens.