Harvard Business Review has an answer to why women get sick of the tech business, despite excelling in it. It is because of "antigens" — elements of the culture that actively repel women. Which is another way of saying that it's full of misogynistic dicks. From Computer World:
We found that 63% of women in science, engineering and technology have experienced sexual harassment. That's a really high figure. They talk about demeaning and condescending attitudes, lots of off-color jokes, sexual innuendo, arrogance; colleagues, particularly in the tech culture, who genuinely think women don't have what it takes — who see them as genetically inferior. It's hard to take as a steady stream. It's predatory and demeaning. It's distressing to find this kind of data in 2008."
The other "antigens" are consequential from this. Women feel isolated, because there are so few women in the trade. Women tend to see less long-term opportunities, because they don't bond with colleagues as a result. IT outfits also reward employees involved in patterns of ostentatious failure and rescue, "the diving catch" — Women, of course, get shit fixed before it starts to break.
Why women quit tech careers [Computer World]