df,
A neighbor across the pasture from me worked as a "production engineer" (whatever that is) for a company that produced optical systems for medical/industrial equipment. He spent a fair amount of time in China overseeing production of his company's systems. As he says" The Chinese have an uncanny ability to meet specifications and produce junk."
In the end though, you are generally correct, it's about quality control by the company that specs and puts their name on the items.
Like you, I will usually look for GM OEM, AC Delco, or Delphi (even though Delphi is no longer wholly owned by GM) first. For political, patriotic, and for USA's own long term good, I look for country of origin too, and when I can find it and/or afford it I buy American.