It's not about purposefully excluding anyone based on immutable traits, it's about not giving anyone preference based on immutable traits. The point is hiring people who are competent and can work together, "pursuing minority candidates" doesn't achieve that. I wouldn't want to be a "diversity hire" myself either, that's a bad position to be in, since everyone makes you feel that you are only here due to the policy, not because you have qualified in the proper way.