That's what I was thinking too.
I've known engineers that were good at business, that were great at business, and that were absolutely terrible at business.
I've known business-types that were reasonably good at managing their departments/organizations, that were great at it, and that were terrible at it, very easily taken-in by suckups and the nature of workplace socialization.
And the problem is that it can be very difficult to know exactly how someone will behave in a role. It sounds like the legacy of the McDonnell-Douglas capture-merger was that the aircraft equivalent of tech-bros got to be in charge. The damn-the-consequences-it'll-get-fixed-later mentality only really works for the short term. The revolution into jet passenger liners has showed us that these products last for decades and the engineering behind them and thus the corporate mindset behind the development and manufacturing process needs to be similarly long-term.
The top brass at Boeing don't themselves absolutely need to have been engineers designing product or working quality or doing floor work with the assemblers, but they need to be able to understand when they're being lied-to, or when there are lies of omission, or when the arguably guilty parties are deflecting rather than doing their jobs properly.
Unfortunately the Boeing shareholders are also partly to blame, because they are looking for short-term profits in a business whose profits are based on product development cycles that require basic research and years of development just to bring designs to maturity, plus the manufacturing time and order fulfillment schedules for individual units that take months to assemble and deliver. When a company in this sort of market sees its owners switch to an eye on short-term profit, that short-term profit only really happens once before the whole thing starts coming apart at the seams.
The new upper management needs to work the stockholders as much as working the departments, suppliers, and employee groups.