Still Bad Fuel Economy.

I was reading an excerpt from a book called "Hot, Flat, and Crowded" by Thomas L. Friedman, and I came across this line that surprised me:

In 1975, Congress passed the Energy Policy and Conservation Act, which established corporate average fuel economy (CAFE) standards that required the gradual doubling of passenger vehicle efficiency for new cars-- to 27.5 miles per gallon-- within ten years.
Not surprisingly, it all worked. Between 1975 and 1985, American passenger vehicle mileage went from around 13.5 miles per gallon to 27.5, while light truck mileage increased from 11.6 miles per gallon to 19.5...

I couldn't help but notice that since 1985, our fuel economy is still remarkably close to 27.5. I looked up the average fuel economy of 2010. I couldn't find an average, but I found this chart: (Data is for 2010 only)

http://www.fueleconomy.gov/feg/FEG2010.pdf

For each class of cars, we can find the average by adding the high and low MPG values and dividing by 2. Working with compact cars, the average MPG is 26.5, and with midsize cars, the average MPG is 30.5. These fuel economy data were boosted by the increasingly popular fuel-efficient hybrid cars on today's market. But still-- the corporate average fuel economy standards in 1985 were 27.5 MPG. How can we, 25 years later, still be hovering slightly over a midsize car's average of 30.5 MPG? And how can any regular car even be below 20 MPG in today's industry?
What are we waiting for?