The goal is a better future, after all, not maximizing fairness in the short-term.
That's why you shouldn't judge by gender, but by performance of the candidate. That just proves my point. If your goal is a better future and you make performance-based decisions, you will minimize biases like sexism all by itself because what is less discriminating than assessing raw performance?
Before you can have an unbiased result, you need an unbiased pool of candidates. A temporary bias in the last round is an attempt to help fix the clearly-broken funnel that leads there. It might not be the best way of doing things, but the plan is not obviously wrong or anything.
Affirmative action is destructive. You are setting up people to fail by promoting them into positions they are not fit to take. Either they are qualified or they aren't. End of discussion. It's the same way with marks. Nobody is helped if a black person with bad marks gets into a college when they should not, and they end up not being able to handle the subjects and drop out later.
Not only that - affirmative action is disrespectful. Women can do as well as men. I believe in it. But that is precisely why affirmative action is obsolete. Only those who think women cannot handle the work and cannot perform on par with men favour affirmative actions based on gender. In the German language, there's already a word for women who were promoted into positions they cannot handle because there are certain quotas to fill as required by law. This is called "Quotenfrau" and is incredibly derogatory.
If someone isn't qualified, then a small bump won't be enough to put them in the job. We're not talking about picking a random person off the street to meet a quota.
There are flaws in affirmative action, but doing nothing about disparities that have self-perpetuating attributes is a pretty bad plan by itself. Top candidates don't appear out of a vacuum.
That's why you shouldn't judge by gender, but by performance of the candidate. That just proves my point. If your goal is a better future and you make performance-based decisions, you will minimize biases like sexism all by itself because what is less discriminating than assessing raw performance?