America is a big country; hybrids make sense for some, but not for others.
If you buy a diesel and drive a lot of miles, you will eventually see savings due to using fuel despite the higher price up front.
With hybrids you pay the higher price up front, but you also have the high costs of replacing the battery if you drive the vehicle a lot of miles. Last I read, when the costs of replacing the battery were included you didn't end up saving money even if you drove a lot.
However, the price of gasoline has been going up, and they have been improving the batteries, so that may have changed by now or in the not so distant future.
For some people there are other benefits to owning a hybrid. I have a friend with a Mercury Mariner Hybrid that loves it not just because of the fuel mileage, but because it doubles as a generator when tailgating or campground camping.
For some people it is worth the extra expense to produce less emissions and direct less money toward the oil industry.
Different people have different priorities.