And I, in turn, have never understood the argument you mention. Regulations have effects, both malevolent and benign. When regulations are enforced, someone wins, someone else loses. If we "clean up the air and breathe easier" as you put, it but millions of people end up in poverty (or worse), is that a net win?

We would unquestionably have cleaner air if we shut down all coal-fired generating plants and banned the internal combustion engine tomorrow. There are excellent reasons to do just that, environmentally speaking. But does it sound like a good idea to you? If so, then you may need to think things through a little farther, I believe.