In my estimation, a culture change is critical. There cannot be an attitude that sees airworthyness certification as something to be gotten around. There cannot be a tolerance for short cuts. The project isn't done until it is done. A baby takes 9 months as it were.
Perhaps review the practice of type certificate grandfathering? Seems like if anything, any new plane, even if based on an old design should still have it's own type, even if most of the data is the same as the old one.
Prove negligence as the facts allow, keep a thumb on Boeing until ample evidence of cultural improvement has taken place, and possibly tune up the regulatory framework to make sales oriented pitches like "no-retraining required" less likely? Or at least define some degree of modification that legally requires pilot/operator retraining?
Then just let the legal system resolve the remaining civil suits?
I don't think the entire company needs to be rendered no more, but a line in the sand was crossed, so I believe regulatory escalation is in this case both warranted and justified.
>Breaking up maybe? Clearly competition in the sector seems to have devolved into a duopoly to some degree.
You can't really break up a company like Boeing; they aren't even vertically integrated anyway. Just like a carmaker, they get their components from other companies. They don't even make their own engines (those come from Pratt & Whitney, GE, Rolls Royce, etc.) the way car companies do.
How we "get over" this is simple, though I don't see it happening in Trump's America any time soon: you prosecute Boeing executives and engineers (the PEs) for criminal negligence, and throw them in prison. The company goes under, and gets bought out by one of its competitors.
As for duopoly, that's currently the case, but China's aircraft manufacturer is working hard on getting their aircraft certified, so if that happens there will now be 3 big competitors in the market, which is generally the sign of a mature but competitive market. If Boeing gets bought out, it'd probably be 2. But I'd feel much safer with Airbus using Boeing's facilities to build Airbus-designed airplanes, which have been properly certified by European regulators.