What you want here is that the amount spent on a person is conditionally independent [1] of characteristics that are irrelevant to that persons performance given the characteristics that are relevant to that persons performance.
Why? Just on topic that leaves out two very, very important things:
1. The process is already inherently unfairly biased towards men and it will take a nontrivial investment of resources to counter that.
2. Although it wouldn't affect an individual's performance, diversity (and other things that don't affect individual performance) can affect team performance and thus need to be considered.
"The process is already inherently unfairly biased towards men"
This is untrue. There are probably all sorts of societal issues that affect whether one enters the tech industry based on gender, but those aren't inherent to the process. It's also not clear that hiring practices will help the problem. A desirable company can improve its gender ratio, but only by hurting the ratio at other companies. (I don't think this is a bad thing.) Something has to cause more women to become programmers, and I doubt hiring practices are the solution.
Why? Just on topic that leaves out two very, very important things:
1. The process is already inherently unfairly biased towards men and it will take a nontrivial investment of resources to counter that.
2. Although it wouldn't affect an individual's performance, diversity (and other things that don't affect individual performance) can affect team performance and thus need to be considered.