[eqvinox]

Question is, why were these things manufactured wrong. It's well possible that Boeing's engineering documents are poor or misleading, triggering human error during manufacturing.

This is of course pure speculation and it might equally well be some single manufacturer pressuring ("optimizing") their employees (or even machines) past the point of reliability.

Either way I'm not gonna fault anyone for refusing to fly on a 737 MAX. At some point you gotta make a call and shift your assumption from "isolated engineering/manufacturing mishap" to "corporate screwed the entire product top to bottom".