I wish more people knew and understood this concept.
It's important to know the impact that you have on a system, especially at large scale. Decades after Goodhart made this law, we still have shoddy credit risk measures that put tens of trillions of dollars at risk just in the US alone. Hell, the last recession alone was mostly caused by the government's choice of credit worthiness metrics.
I'm not sure why you think these things are mutually exclusive. And as far as Goodhart's Law is concerned in this case, they're intertwined concepts.
The government's choice to allow securities rated by S&P/Moody's to be treated as gospel allowed/encouraged banks, insurance companies, GSE's and pension funds to take far more risk than was systemically reasonable.
It's important to know the impact that you have on a system, especially at large scale. Decades after Goodhart made this law, we still have shoddy credit risk measures that put tens of trillions of dollars at risk just in the US alone. Hell, the last recession alone was mostly caused by the government's choice of credit worthiness metrics.