I do think that people in metro areas like NY, LA, SF, don't realize what it's like to like in the more sparsely populated parts of the country, and that is still the biggest limitation in my part of the world. 150 miles might be barely adequate _IF_ there were near instant recharges. If I want to test drive a new Ducati, I have to drive 500 miles round trip (and have done it in a single day multiple times)
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.
The solutions already exist if we find a way to deploy them. We even have the technology today to recharge your car wirelessly while it's driving.
With wireless induction charging, you won't have to stop driving until it's time to rotate your tires or use the restroom.
http://spectrum.ieee.org/tech-talk/green-tech/advanced-cars/...
That's exactly what the battery factory will do. That is what Tesla is doing: they are going the long way, not dismissing the technology while waiting for a black swan to appear at the end of a rainbow that will save them. Because there won't be one.