And perhaps that's a fair comment, but wouldn't you say that contributing to cleaner air is probably a good thing if it didn't cost you more, or require a significant loss of performance? Some of the new hybrids are fairly nice cars.
Most gas vehicles don't emit that much anymore, the majority of vehicular emissions come from poorly maintained vehicles that the owner is finding a way to avoid government regulations with. Thanks to improvements in both the engines and the exhaust system many newer all gas vehicles will actually emit cleaner air than they take in when run in many of the larger cities in America. So the hybrids contribution to clean air is questionable, they still burn gas, depending on the model and what you're comparing it to their gas savings isn't that great, and we've gotten much better as a whole about burning gas cleanly.
Buy whatever car you want, but if you're buying a car for a specific advertised reason you should take the time to make sure the ads are truthful. My "official" stance on the hybrids (not that anybody really cares, just putting it forth for clarity) is: wait and see. I'm in software QA and have the standard QA person's lack of trust for new technology, I want to see the performance of the 3rd production generation of these things, I never trust the 1st production generation of anything and rarely trust the 2nd. Hybrids are in production generation 1, so I'm waiting and seeing.