Boeing and Airbus both source avionics from the same third parties. The 737NG uses Smiths, but everything else in the Boeing fleet (and all newer Airbus airframes that I’m aware of) come from Honeywell. While you can fault Boeing for not finding this, the vast majority of the fault lies with the OEM.
Even if this particular problem is not Boeing’s fault, but Smiths’, the whole 737MAX saga still puts Boeing in a pretty bad light – cutting corners on security, outsourcing their software to dubious vendors, etc.
The Daily podcast (NYTimes) did an episode last week called “Boeing’s Broken Dreams” where they interviewed a former Boeing safety manager turned whistleblower. Definitely sounds like there was a major cultural shift over the past decade or so.
There's plenty of bad light to go around. Say company A builds a faulty part, then a stack of ten subcontractors test it and fail to find the error, and finally company B tests and accepts it. Who is responsible for the eventual failure in the field? They all are, because they all had veto power.
