When a measure becomes a target then players will attempt to break the correlation with the thing it's supposed to be measuring, because to win you must be optimised for winning, which is expensive, and discarding the integrity of the game is often a good strategy. If the players can do that then it's a bad game. If the players can't do that then it's a good game.

When students do exams it's explicitly a target, and a measure. Why do we not say that examination results are bad measures? And if we do say that they are bad measures why do we use them?

Think of the people doing the measuring as the selectors, like the crowds at a football match, or potential mates in a sexual competition, or the housing market. The buyers (the crowd, the female, the house hunter) measure the options against a set of criteria. The criteria that each of the criteria being used to make the buying decision are the 4 mentioned, otherwise it ceases to be a good measure.

In other words, don't hate the player, hate the game.