I live in Wyoming, a state with 100,000 sq miles and around 500,000 people, and I have been commuting for over 25 years. I totally agree with the mummygoneona cycle..com article as to the reasons why few people commute or ride much.
It is hard to ride to work in an office for any distance unless there is a locker and shower at the end and look ok for work.
I have doped out a safe route but my son in Chicago will not ride the excellent bike I built up for him because he does not have a safe way to go. Safety is a real concern.
Many new to biking find gears intimidating and riding, especially in traffic scary at first, and don't feel they can fix flats etc they may have.
Weather, especially high winds, ice and snow seems to be daunting.
Another factor is that until you ride enough to be comfortable on a bike the very real benefits are not realized......the stress relief of a ride home after a tough day at work, the endorphin buzz from the ride, the ability to eat a bit more and still lose weight, and knowing that if you ride in you will ride home so no need to go to a gym, as examples.
Until riding is safe and the rider learns how to set up a bike for safe travel in a range of weather, and how to dress so as to be comfortable, many people just aren't going to see this as something they want to do. In the mountain west mtn biking is very popular as it is usually done in car free areas and often in groups so it is safer on many levels. Unfortunately, it is a bit elitist as high end mtn bikes are very expensive. Still, anything that gets someone in a bike is a good thing in my opinion.
I know this doesn't specifically address why women are less likely to ride, but when biking is more normalized as a common method of transportation and not seen as only for racers and athletes, I think it likely that will change.