Observations really.

I've seen this pattern many times on smaller and larger scales. Betting on a technical manager is almost always the correct bet to place.

Being an internet commenter doesn’t require any particular expertise in the thing…

I think GP’s claimed belief “among managers” is true for a very small sliver of the management ranks (and I think a smaller sliver than in the internet commenters’ case).

It certainly seems true of a breed of MBA. When interviewing candidates for PM it's interesting to see the breakdown in people who care about how the product works and those who consider it a widget to be put in a box. "Bring the customer demands to the eng team (without providing a useful translation)".