I know what you mean, but if you look at market history the most profit has always been made with revolutionary products that many could make and yet did not. Be it a cheap car, a sugary drink , a place where you get a whole meal in 5 minutes or a good looking cellphone, it does not matter.
Most high MPG cars are a market anomaly because on one side they are intended for frugal people and on the other side they usually cost more to buy than regular models.
Can you smell the billions of dollars just waiting for someone to pick them up from the ground?