When I go to jazz festivals, there is often a long line for the men's bathroom, with no lines at all for the women's room. Many women love to make comments on how nice that reversal is. But it points to a simple fact: jazz is not as popular with female listeners as it is with male listeners. So why should we be surprised to see female musicians eschewing it as well?
The article really gets to the point right here, IMO: "I asked a jazz teacher once why he thought there was such an imbalance. He thought for a moment and said, 'Well, jazz is a bit of blokey art form'." Let's face it: it's kind of an egotistical art form (I love jazz, but still). I can imagine women being put off by what they may perceive as a bunch of macho posturing.
I had a GF years ago who identified as a feminist. She once told me that if I wanted my music to appeal to women, I had to aim for their hips. She stated that men like to listen to music, but women prefer to dance to it. I don't know if it's true or not; it seems like a bit too much of a generalization. I do know that when I went to see Medeski, Martin, and Wood a few years ago, every time they would get more abstract, the women in the audience would start talking to each other. Then the band would hit a groove, and the women would stop talking and start dancing.