In fairness, your second paragraph falls victim to the fallacy of "the problem you mention does not exist because solutions to it are too hard". Yes, the thing

In fairness, your second paragraph falls victim to the fallacy of "the problem you mention does not exist because solutions to it are too hard". Yes, the things you mention are hard to design/decide upon, but strictly speaking that's not an argument against the parent (ie it's not that bonuses based on race/gender are wrong because they're hard to do).