This graph says it all, I think. Is it really conceivable that women were more interested in computing when it was all about hand-coding assembly for a modest amount of money, and less interested now that you can make >$100K/year doing Rails from home?
http://www.npr.org/blogs/money/2014/10/21/357629765/when-wom...
There's tons of evidence that women are excluded from our industry, at every level -- high school, university, and even the ones that graduate and go on to work in the industry drop out at a very high rate. Other scientific or mathematical fields do not have the same problem.
You will probably now try to bury me with various quibbles, because you can argue against any statistic. but maybe you could try ASKING A WOMAN.
Anecdotally, I know many women who have since found coding later in life. I've heard several times that they wandered into some science or computer club early on and had horrible experiences and left. They're coming into it now, mostly due to the high demand for engineers such that the industry is (reluctantly) hiring people who don't have the ideal background, and actually training them. So these women are finding out, for the first time, that they aren't bad at technical things. It was just that the field was so gendered, and they came from environments that were strongly biased.