Because there are people who actually care about clean air.
> Contrast this to opposing civil liberties restrictions, which can very easily and effectively be spun by political opponents as leaving America open to terror attacks.
Supporting environmental legislation is very easily spun by political opponents as costing America jobs.
The amount of political opposition to environmental laws is otherworldly. There are a few companies here and there making money off things like Rapiscanners, but the companies whose profits are hurt by environmental regulations account for trillions in US revenue each year. Everything from Exxon Mobil to small chemical plants with $10 million in revenues. And while "think of 9/11" has a certain impact, it's not only fading but even at it's peak never compared to the visceral cultural opposition towards environmental laws. Industries impacted by environmental laws are literally ways of life in many parts of the country. People in Pennsylvania, West Virginia, etc, fight to allow coal companies to keep poisoning them as part of their cultural heritage.
To put things into context: adding up U.S. box-office, DVD/Blu-Ray/etc, and music (digital and CD) revenues doesn't break $40 billion a year. Apple by itself made more than that last quarter. Exxon by itself makes 10x as much in a year, and there are 8 other petroleum companies in the Fortune 100. But environmentalists somehow manage to get some wins. While tech people whine incessantly about how "the system" is why they can't make any headway against the RIAA/MPAA.
