Punishing a corporation is easy, but the government hates doing it for obvious reasons. It means ruining something which is useful to you and punishing tens of thousands of completely innocent people, with inevitable layoffs.
What Boeing really needs is a complete change in management culture, as that was the real root cause for the MAX disasters, but that is impossible to enforce, you can't even really verify that it has happened.
I also think people don't understand how extremely lucky Boeing is. If all of this had happened during a time of low demand the company would be facing a far more dire situation, likely with many major airlines canceling orders. But since airplane demand is very high and order books are full, airlines have to keep their orders at Boeing if they want new planes.