This is a somewhat one-sided perspective. The end polluter is often the US government itself. Do we hold the government officials to that same standard? How about the citizens that elected them?
When Congress continually undermines and rolls back the agencies rules, who actually is to blame? The regulator? Congress? The voters?
The point I'm trying to make is that this scenario isn't as black and white as one might think. It's easy to be an absolutist about it when it's not your child burning to death.
For some reason, even though plenty of people are ready and willing to buy and sell murder, we still don't allow it.
Both can be bad and disallowed.
The US government knew it was bad, bought it, and then knowingly created the vast majority of contamination.
They then Sue manufacturers like 3M, while continuing to buy and use it and cause more contamination.
It is like buying a knife, stabbing a bunch of people, then suing the manufacturer while still running around stabbing people. It screams of misdirection.