I think it is very possibly a result of culture in America and to a lesser extent, Europe, showing people working in technology as unglamorous, lonely nerds with questionable personal hygiene.
Witness the many TV shows making fun of STEM-concentration people, The Big Bang Theory, The IT Crowd, etc. In any film, the hacker will typically be shown as the over-eager, quirky, physically weak character (think Charlie Day as the kaiju scientist in Pacific Rim). Unless the film is something edgy like the Matrix, people always expect to see computer professionals as low-status individuals.
In my opinion, this results in women being afraid to enter these fields, because they are painted as having low social worth even if they have high economic worth. (BTW, if you live in Silicon Valley and are used to coffee-shop discussions about your favourite JS libraries, remember that it is a distorted reality field; if you are male and work in tech elsewhere in the States, the most people will come up with is "Do you work in IT? Oh, I see...")
On the contrary, in the former Soviet Union, scientists and technologist had a high social worth. Boom, 58% of engineers were women, as the article says.