"I believe that our problem is individual desire versus the common good." p8

I don't disagree.
But my statement:
"The barrier is not scientific possibility, it's economic disincentive, and societal status quo." sear

is stated more objectively.
You are right.
The reason for the societal status quo is selfishness. But let's be realistic here. Persons in cold climates can stay warm in Winter, and persons in hot climates can stay cool in summer, by consuming vast amounts of energy to heat or cool their poorly insulated homes.

- or -

They could maintain precisely those same temperatures, consuming substantially LESS energy; IF the government would simply raise the building code standards on insulation.

It's a similar story with CAFE / MPG.

The Corporate Average Fuel Economy (CAFE) of an automaker's fleet could to some degree be whatever Congress says it'll be.
There are limits.
Congress couldn't declare the standard is 10 Billion miles per gallon. We don't have the technology for that. But in the U.S. persons own and operate automobiles that weigh twice as much as they should, and get half the fuel economy they should.

You call that "individual desire". I called it "economic disincentive, and societal status quo".
In my opinion these are different words applied to the same phenomenon.