When I was in math class during high school and college, I had two different experiences. In high school I was given credit on a math test only for the correct solutions that I turned in. While in college I was given credit for the steps that I took to arrive at an answer even if that answer was incorrect. While high school only accepted "perfect", college embraced "good". I may not have arrived at the "perfect" answer, but my teacher could see the steps that I took and affirm the positive steps while at the same time pointing out where I had strayed. In high school math class, the pursuit of perfect belittled the good.
The perfect belittling the good is something that you can see when an adult tries something for the first time. For instance, many adults do not like to dance in public in part because they are not perfect at dancing. We feel that since we "cannot dance" (read, we are not perfect dancers) we do not dance. And since we don't dance we remain crappy dancers. We do not see practice as making good progress that is to be affirmed. We just sit on our hands and marvel at those who seem to be able to dance "flawlessly". The pursuit of perfect belittles good.
You also see the pursuit of perfect belittling good when it comes to public policy. One party might propose a solution to a situation, fully aware that the proposal will not perfectly solve the problem. Critics point out the imperfections in the proposed solution and deem it as garbage since it is not going to address the problem 100%. Since the solution is not perfect it is belittled.
Good does not have to be the enemy of perfection. Just because something may not be perfect, it still can be good. Just because humans are not perfect, humans are still good.