Test pilots approval
Whether or not MCAS played a part in the Ethiopian crash and to what extent it did in the Lion Air, I am puzzled how a lot of posters here blame the engineering community. From what I remember from working for an aircraft manufacturer only a few years back, the design decision making process for systems relating to flight control thoroughly involved the test engineers and test pilots, who can't be blamed for lacking aviation culture.
If the design is at fault, then the whole 'system' from management, engineering, test pilots and certification authorities played a part in aligning the holes of this Swiss cheese.