Apathy most likely. Fuel efficient cars were all the rage and getting the spotlight when gas was pushing the $4.00/gallon mark. As soon as gas prices plummeted so did the desire to drive a 'gutless' hybrid or fuel economy car. Instead desire for the SUV has once again increased. It goes in cycles, the majority of drivers do not care about fuel economy unless it begins to tie up money that could be devoted to 'play'. I remember it used to take near $60.00 to fill up my malibu. I did this twice a week so literally I did not have any extra money to put towards things that I would like to have done as most of it was tied up in fueling my car so I could work.
That being said, the fuel scare did leave a mark as people are more open to the idea of owning a fuel efficient car vs. a truck or SUV