Examining gender bias among airline pilots is rather late in the metaphorical career pipe to be looking for a leek or cause. A lot of the "reasons" given in that article absolutely fail to explain the gender disparity in private pilots. The whole "its a demanding career" reasoning (and all its annoying derivatives) is bunk since it doesn't explain why so few women want to fly for the sake of flying as a past-time! About half of all pilots aren't doing it as a career. Consider the statistics:
The gain in commercial and ATP certificates were the most significant. The percentage gain in private pilot percentage was due to entirely to having a lower attrition rate than men! But in all cases, women just didn't make up that great a percentage. Now go figure out the percentages for the non-pilot fields in those tables - one field stands out! Do any of the "reasons" stated in the article explain the percentages in those fields!?
Since only ~0.3% of all U.S. citizens who are likely eligible to become pilots ever do (assuming everyone who drives a car is eligible; ~190,000,000 drivers http://www.fhwa.dot.gov/ohim/onh00/onh2p4.htm) the low percentage of women among the piloting ranks may be simply due to a secondary causal action because of the extreme winnowing that occurs at the extremes of any bell curve.