Often a goal set is not based on a single set of arguments justifying it, but because it is a good compromise point between multiple arguments, motivations or interest groups. For example human rights formulations don’t perfectly fulfill any groups desires (utilitarians, egalitarians, deontological groups, religious motivations etc.) but are a point of overlap between their goal sets (both utilitarians and deontologists both think torture and murder are generally bad). Similarly with GDP, economic growth is a shared interest of several groups in society.
So some instances of goodhearts law may be an observation that particular sets of goals are not being perfectly fulfilled.
Often a goal set is not based on a single set of arguments justifying it, but because it is a good compromise point between multiple arguments, motivations or interest groups. For example human rights formulations don’t perfectly fulfill any groups desires (utilitarians, egalitarians, deontological groups, religious motivations etc.) but are a point of overlap between their goal sets (both utilitarians and deontologists both think torture and murder are generally bad). Similarly with GDP, economic growth is a shared interest of several groups in society.
So some instances of goodhearts law may be an observation that particular sets of goals are not being perfectly fulfilled.