Someone who says "Simply pick the non-goodhartable measure" is a one-ply thinker.

Multi-ply thinkers can see that Goodhart's law arises, inexorably, in complex domains.

But you can't see it in any single ply; it is inherently a multi-ply phenomenon.

So smart single-ply thinkers will acknowledge the phenomena but miss why it is so important and inescapable.