This is not how companies work. Engineers at Boeing didn't have a design labeled "not-good-enough-but-cheap" and another labelled "more-skookum-but-is-expensive" and because they were bad engineers decided to go with the cheap one. It's a systemic issue due to cost cutting by, you guessed it, people MBA's.
No engineer, if given the choice, would have re-used the old plane design instead of designing a fully new, modern plane, that was an MBA trying to cut costs.
No engineer, if given the choice, would have put the plane through as little testing as they did or sold it as not requiring much training for pilots, that was an MBA trying to cut costs.
No engineer, if given the choice, would have separated the manufacturing facility out of Boeing, that was an MBA trying to cut costs.
These are decisions that were pushed by higher ups (with MBAs) that engineers have to live with. They aren't "wrong" decisions, there is nothing in them an engineer could look at and say "this will, 100% cause a failure down the road and I demand we not do this". What they are is steps in the wrong direction, steps away from the "best" decision that could have made from a safety and quality standpoint. Take enough and eventually they add up into what happened.
I think the best way I can put it is if, as an engineering org that deals with real world things, you aren't pushing towards best practices, higher standards, and technical excellence than you are either stagnating or declining. In either case your quality will decline without anyone doing anything "wrong" as you end up with people with increasingly less experience and resources being asked to do more work. And the worst part is you can get away with that and often companies do. But if you go to far eventually you cross a threshold where cumulative effects push you over the boundary of failure.
