While I generally agree with most of your sociology observations, I feel you're heavily discounting the real impact to reliability that relates to design and specification differences between the domestics and Japanese auto-makers. In the 90's, I was a process engineer for an automotive wiring manufacturer supplying to both domestics and Japanese harness makers. The Japanese clients mandated cold-weld free segments for use in all of their cars with no exception. The domestics were ok with <=2. A cold-weld (physically crimped) going through hot/cold thermal cycles will eventually break in a car and is a messy quality risk because wiring controls a huge amount of car function and depending on where the weld ends up and whether it is a partial or complete break - can result in hard to diagnose failure symptoms (e.g. flaky lights, complete outage, etc ...). We used to charge more (which the Japanese clients happily absorbed) for the weld-free wire because the process lines would need to either be re-strung up for each pass (lower line utilization/efficiency) or we had to physically cut out the weld in the wire based on the detector's marking. This small difference in specifications and acceptance criteria will result in reliability differences downstream. I have no doubt that other suppliers could tell you equally divergent requirements which all may feel small in isolation, but amount to large reliability concerns for the system overall. While I understood the cost-control desire of the domestics, it always felt like a short-sighted decision to accept this type of risk systemically. It no doubt helps to have caring owners, but the reputation that draws them is based on design and specifications made early in the product's design life cycle.
Interesting Side-Note: When I first started, there was an anecdote/story about a weld that had made its way accidentally (weld detector inadvertently turned off for the wrong run) into a production lot. This lot was used in a late design life cycle batch run (~50K cars) for one of the large Japanese manufacturers who were planning on announcing a new design model year for the upcoming year. When the auto maker heard that this weld had made its way into the batch run, they gave our company two choices: Either buy the 50K cars or pay for the auto manufacturers engineers to comb through each car to validate the wiring was weld free. I don't know which choice was made, but the there were alot of human and mechanical systems put in place to make sure the weld detector and the client requirements were well marked and understood for all runs thereafter. It was a fireable offense to mess with that detector in any unauthorized way.
Interesting Side-Note: When I first started, there was an anecdote/story about a weld that had made its way accidentally (weld detector inadvertently turned off for the wrong run) into a production lot. This lot was used in a late design life cycle batch run (~50K cars) for one of the large Japanese manufacturers who were planning on announcing a new design model year for the upcoming year. When the auto maker heard that this weld had made its way into the batch run, they gave our company two choices: Either buy the 50K cars or pay for the auto manufacturers engineers to comb through each car to validate the wiring was weld free. I don't know which choice was made, but the there were alot of human and mechanical systems put in place to make sure the weld detector and the client requirements were well marked and understood for all runs thereafter. It was a fireable offense to mess with that detector in any unauthorized way.