Because my solution isn’t deregulation, its accountable private sector regulation, that isn’t dependent on govt funding.
If no outside company wants the responsibility as you suggest allow Boeing to self regulate(as they currently are under the system you favor) but remove the govt. shield, and hold them fully liable.
Boeing killing people and noone going to jail is absurd.
As I mentioned this system already exists for ships and offshore assets due to the historical reasons (each country has its own private certification company, and those of the major countries exist for centuries).
The consequence that the libertarians would love is that now there is a market for certification in this industry, and so there can be different regulators for different systems of the same ship or offshore asset.
The other consequence - manufacturers are inclined to choose the most bland regulator for each system, bringing down the industry standard.
The other consequence - no one perseves the regulators responsibility as important and they don't go to jail after an incident e.g. after the Deepwater Horizon no one talked about the responsibilities of ABS and DNV, that did find training problems of the platform crewmen, while the state regulator non-compiting on the market might have blocked the platform construction after finding the untrained crew.
Edit: do you invision the regulation market bringing down the industry standards or you prefer monopolies? In case of a monopoly, state monopoly always works better than the private one.