It's not a perverse incentive, there is a limit to it. And it has a counter balancing incentive in the form of having to run for an election. If you passed bad laws for the sake of metrics you get voted out because there is someone else that wants to do better than you. A perverse incentive is not the same as compensation for doing your job.
Bonuses and promotions always go to those who exceed them, and "improvement plans" or "restructuring" is reserved to those who miss.