The inability of leaders to understand Goodhart’s Law is always a sight to behold. They see a number go up and pat themselves on the back for how well their employees are making it go up without ever wondering if the thing they care about is happening.
This is one explanation, sure.
Isn't it more likely that they simply don't in fact care about the "thing they care about", only the metric?
They can plot the metric on a chart and receive praise, so that's what they're interested in.