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 quite tech careers [Computer World]