It's the numbers - when a department is told to cough up 20 names they cough up 20 names. They don't admit they have 25 slackers and cough up an extra 5 names, and they won't try to fight to keep 5 who are good and only give up 15 names, because either way would mean admitting that they knew in the first place that they had slackers on their team.
So when the numbers come down, no one is really a slacker, like Pacino said, it's just business.
Now...if it was an edge case, i.e. : I need one more name for the list, I've got two people of equal slackiviity, but one is a (fill_in_the_blank gender/race/identity/breed) X, the other is Y, do I choose X over Y in order to keep my X quota kosher?
You could toss a coin, but that's an open admission of stupidity and lack of ethics. So you choose to satisfy the quota, except you BS yourself in your mind that the quota-driven person really was the better one to keep.
So there it is: -ism - QED, no way around it. It's funny how an "ism" becomes more of a problem for some people depending on which end of the shaft is heading towards their rear end.