Even if the criticism is not always perfectly informed and in some cases I would deem unfair, just the noise, attention, fuss probably keeps powerful officials or agencies on their toes. And they should be on their toes when it comes to the use of deadly force.
A lot is gained through experience, but experience teaches some and not others. Effectiveness and excellence, whether or not they were attained by simply having the knack or through the school of hard knocks, is really what you want to reward.