I would hate to see the aviation world striving for 50:50 representation of the sexes - if you're interested, do it. If you're not, don't bother. There's nothing worse than forced equality.
The days of flying being intense physical work are long gone.
If a woman can be a supervisor or run a business she can run a crew and fly an airplane.
Traditional role models still play a factor as does the male-female brain thing.
However not a good enough reason to not promote it among girls/women as a career choice.