That's only true to the extent that the chosen measure was only coincidentally something that looked like a good measure to start with; if you were actually measuring the true feature of merit, making it a target wouldn't make it a bad measure. Making a measure a target incentivizes discovery of its deficiencies, if any, as a measure.
I agree with you in the narrow sense, but I bet you can't think of a metric that should be hyper-focused on for any purpose. Even something like "Lives Saved" fails pretty hard if you do it hard enough.