The core issue causing the quality control issues with Boeing is actually that they are outsourcing more and more of the design and manufacturing of their planes, and then squeezing their contractors, knowing that their contractors don’t have any other options, aerospace is both regional and consolidated. Boeing will gladly point out whenever there is a failure that it is the fault of the contractor that designed the relevant part or system, but it’s generally not that the contractor was incompetent, but rather that they were given an unreasonably tight budget and forced to deliver something.