I'm hoping someone here knows what this means. A product care plan for
a tv I'm considering purchasing for my parents states that it doesn't
cover inherent product defects. What does that mean?

The plan does state that it covers parts and labor costs from failure
due to defects in workmanship and/or materials, normal wear and tear,
dust, heat, humidity, and power surges.

Inherent product defect sounds like it means the tv was built bad, and
in that case, it should be covered.