The workers on the line were only part of the problem. US Automakers in general were slow to implement effective assembly techniques and robust fixes when problems did occur.
US manufacturers back then had extensive option selections, about everything was available on any car. And US vehicles had extensive body and interior changes almost every year. That made the vehicle assembly process very complex. The Japanese imports on the other hand were bought off the dealer showroom floor here in the US as the car was. Possibly the only selectable options were things the dealer did like floor mats or paint sealant. At that point in time Japanese durable goods design and manufacturing was way ahead of how the same things were done in the US.
Best practices like: statistical process control, gauge R&R studies, design for manufacturability were in use in Japan in the 60’s. It was not until the import car invasion occurred that US manufacturing implemented similar practices to improve vehicle quality. The US manufacturers with a captive and growing market had gotten lazy. Japan had rebuilt their manufacturing base after ww 2, with help from the US, and got it right.
Today manufacturing in the US is as good as it is anywhere. It is advantages that off shore manufacturing has with low wages and not being held to environmental laws that stops US manufacturing from dominating.
