Agree with this point completely.

Ideally it seems as if you'd want someone with administrative capabilities and focus but with enough understanding of the tech and business side that they're able to understand context and conversation.

Problem is, although its easy to find administratively capable resources who you can pay a decent salary to retain, the minute you require them to understand broader context the incentive structure changes as this is inherently more work.

To me that is why Product Managers who's focus is a single product should also take over administrative tasks on that project. It gives them an opportunity for "field time" as stated by another poster as well.