Vehicle emission and fuel efficiency standards are a great idea. The stupidity was allowing a "light truck" exception at all. It made the manufacturers turn to manufacturing and promoting what should be work vehicles to rich idiots who need nothing larger than a regular car (but can easily be upsold on something they don't need)

America is already fucked, given how awful its urban sprawl is. Trucks used for commuting and not haulage just makes it double fucked.

The exception being blamed on "stupidity" makes it sound like an oversight.

It was not an oversight. It was corruption.