Quotas are an interesting thing. In my home country if you want to study medicine/dentistry/pharmacy there is a 50/50 M to F quota in universities. For the entrance exams women perform much better on average than the guys. It's possible that a guy with a score below the upper half of accepted males won't have a high enough score to get accepted if they were female. Yet as soon as they start university, the guys on average perform much better, even those who performed poorly at the entrance exams. The thing here is that if you didn't have a quota, you would probably have 20% M and 80% F studying these 3 subjects but would end up with a weaker work force. Quotas aren't necessarily bad, but it's difficult to set on a proper quota to best represent the population and ensure that you aren't hurting your business.