Your observations are very similar to what I witnessed yesterday, except not one of the hybrid drivers I encountered was remotely aware of mileage. Our driving techniques are in the absolute minority, even among hybrid drivers.

I drove from the OC to Santa Barbara and back (95% freeway; about 280 miles round trip) and there had to be at least 15 Priuses (Prii?), 10 HCHs, 5 escape hybrids, and a couple Insights. A Prius was tailgating me for a mile or so. I guess HCH vs. Prius is the new Mustang vs. Camaro since the Prius driver gave me a nasty look as he passed me. When I left the OC, I was lined up with another HCH at a redlight. When the light turned green, I could have sworn I heard tires squeal as he dumped the clutch. I've never witnessed a hybrid take off so quickly.

Every single hybrid was driving significantly faster than I was and more than half had the sacred HOV lane sticker. I speculate that many of the hybrid owners (at least in California) are more concerned with the time savings of being able to use the HOV lane during traffic hours than achieving high fuel economy. I guess driving 80-90MPH in a hybrid is still more efficient than driving that fast in most other cars.