To be fair, the problem this time was with QC - not with engineering.
Why this happened? Massive cost cuts ordered by management, which led to cut corners, or cut trainings, or both. If ing. Or MBA is irrelevant. If I have to guess, I would point to an MBA
As the saying goes, “you can’t test quality into a product.”
But that also seems like splitting hairs. The problem is not one of engineering design, to OP's post.
If cars are leaving the factory without brakes on, you shouldn't start firing engineers for designing a car that's possible to build without brakes.
Shareholders are more than willing to reward the relevant executives for cutting spending, but they rarely hold the same people who made those cuts for issues stemming as a consequence of the aforementioned cuts.