Pretty much, they want the most profit possible. It's been getting worse over the years with other products. I have lost time on simple jobs because of issues that I needed to fix with new parts. Most of the time it's nothing drastic, but still something that should have never existed in the first place. Water pumps, radiators, alternators, fan clutches, brake components and more have cost me time I can't get back. I understand a defect once in awhile, but when the same issues are never fixed months later, that's a problem, especially if a shop has limited options in the area.
I would love to share my history of getting bad autoparts, I do have some that I really remember well. Maybe I might do another thread in the future where everyone can share their stories with defective or poor quality parts.