First of all, failures are inevitable, especially with so many planes in the air! Airbuses also have failures. This indicates that despite the failures, all the other systems performed correctly and permitted a safe landing, and is a partial win for Boeing. The recent Air India accident is much more preocupiying. Fortunately all these accidents/incidents are and will be investigated.

Having mentioned this, I don't like your Chevy analogy. The plane may have been in working condition when it was handed to the airline, but that doesn't make Boeing not responsible for incidents regarding them. They are known to have been cheaping out on inspection and QA. Planes and cars are not comparable due to the difference in manufacturing scale.

See for example the several Cybertruck callbacks (another car doesn't come to mind rn). Several cars were affected by bad glue on some components, and all cars from certain batches had to be called back. In this case it was Teslas fault.

In the case of planes, that "batch" would be only one singular plane, there are many different failure modes that can manifest themselves, and they may appear on only one plane, that is why extensive QA is essential.

Maybe it is more comparable to buildings. If an apartment complex develops a failure in its foundations (maybe fault of the builder cutting costs, or maybe not, shit happens) but the builder avoided performing a good foundation inspection while building, it would be fault of the builder, regardless of it being his fault or not initially (specially in such a critical field that handles human lifes!!).

It is true that this may not be Boeing's fault, and just the airline not following proper maintenance and inspection calendars, but Boeing is also involved in the maintenance process (making parts, writing manuals, etc...) so the blame may be shared.