Where do you suppose we would be now without the government imposed emission regulations? Sure they cost us money. But in the long run we're better off. It's been a long time since one of our rivers caught on fire and we can actually breathe the air in our major cities. Acid rain isn't ruining our pretty paint jobs and our municipal water supplies are safe to drink. Do you really think any of that would have been possible if pollution control was voluntary?
Remember the early 70's when the automotive industry was going through the same thing with gasoline engines? People cried about how pollution control was wasting gas and crippling power. Fast forward a few years and we're getting more power and better economy from smaller engines and the emissions are almost non-existent.