I agree. The correct way of looking at this is we should try to attract as many talented people to scientific fields as possible. If we can identify any group of any description that is under-represented (women, ethnic minorities, people with a particular hair color, whatever), it is an opportunity to find more talent. Identifying a large group of such under-represented people gives us the change to remove the (real or perceived) barriers for a lot of people at once. This is a great efficiency compared to doing this for each individual smart person, who has their own varied reasons for avoiding a scientific field!
As a side benefit, increasing the number of women tends to decrease the 'locker room' behavior that can sometimes be found in a male dominated setting. Many of us men appreciate that too.