There have been plenty of such studies. There is no "exodus", the industry has been dominated by men for a long time. It doesn't change because at each stage of the educational pipeline where women could make a choice that takes them towards software/hardware, a chunk of them drop out, until you get the ratios in the job you get today which are more or less similar to the ratios that graduate with CS degrees.
They drop out partly because, inconvenient though it is to admit this, they tend to get discouraged more easily. There are stats showing that women stop searching for software jobs after X rejections, men after Y (on average), and that Y > X. Google found that women were getting promoted less than men simply because they weren't putting themselves forward for promotion as often. That pattern crops up again and again - women hold back when they could push forward.
That is not an accurate representation of the research. See this public summary of a (sadly, paywalled) HBR paper on the subject [https://hbr.org/2016/08/why-do-so-many-women-who-study-engin...]. At every stage of the educational pipeline, a chunk of women do indeed drop out. The cause, however, is often an encounter with sexist culture along the way.
The subject of insecurity does come up:
> Throughout college, men and women succeeded equally in the classroom. However, we observed that women started to doubt their problem-solving abilities more than men. [...skipping long illustrating quote]. Women were also much more likely to look to others—teaching assistants, professors, and advisors—to affirm, and reaffirm, their confidence. Men did talk about doubting themselves, but they did not necessarily seek reassurance from others. We found that this search for positive cues carried over into expectations for feedback from supervisors in internships and jobs."
However, it is not at all the only phenomenon at play. More discouraging is the gendered treatment they receive from professors and, more importantly, colleagues.
> For many women engineering students, however, their first encounter with collaboration is to be treated in gender stereotypical ways, mostly by their peers. While some initially described working in teams positively, many more reported negative experiences. When working with male classmates, for example, they often spoke of being relegated to doing routine managerial and secretarial jobs, and of being excluded from the “real” engineering work. Kimberly wrote, “Two girls in a group had been working on the robot we were building in that class for hours, and the guys in their group came back in and within minutes had sentenced them to doing menial tasks while the guys went and had all the fun in the machine shop.”
> There were also descriptions of being treated differently by professors. Rachel described when her team (the only all-girl team) won second place in a design competition: “Our professor wanted to get a picture of our prototype and us. We picked up our prototype and were all smiling and looking all professional; then he said: ‘You guys look like professional catalog models; this picture could go in a catalog and you could sell big time.’”
> Men, on the other hand, described mandatory group design projects as exciting turning points, where theory and practice come together. “I made a pretty big stroke of progress last week,” one student wrote in his semi-monthly diary, “I ended up proving the professor wrong on something she had done last year, which actually helped us find better results (well, also more correct results)… It’s really a blast working on something like that.”
Anyway, there are more quotes available, if you want to look at it yourself.
Note also that there is one other factor they address that isn't related to sexism in the field (but perhaps to broader sexist acculturation in society) - women are more likely to want to work somewhere that is "contributing to society". Part of what's going on here is that it's not considered quite as socially acceptable for women to be ambitious for ambition's sake, at least not in the way that it is for men. But I don't think that's something that the engineering culture enforces, I think that's something that's internalized.
I think my representation was accurate and the sections you quoted rather support that.
So some women felt like they got assigned sucky roles in group projects. But so what? Men get assigned sucky roles in group projects too. Every group project has that problem: some roles will be perceived as more desirable than others. There was an assumption there that the girls "sentenced" (gosh, what emotive language) to some other role simply because they were girls, and not because they were simply less pushy personalities in general. But no evidence is provided either way - they never asked the men why they did that, or if they even perceived the women as upset. Maybe an assertive woman would have steamrollered shy men in the group, I've seen that happen. Sexism is asserted as the cause and, as is always the case, that lazy assumption passes unchallenged.
In another case, the women were complimented on their appearance by a man, something that happens in every work environment and every job around the world. This is related to gender ratios in programming specifically, how?
The last quote - I'm not even sure how that's related to sexism. It appears to show a man enjoying the studies.
I guess if women perceive things like the internet as not "contributing to society" that would be one of the non-sexism related problems women cause themselves. OK, sure, if they believe that, that'd explain some of the gender disparity, but again - so what? Lots of men believe the opposite. If true, it's a self-imposed handicap that women can discard anytime they like. Besides, I'd much rather work with people who believe their work has a higher purpose than people who are simply ambitious!
They drop out partly because, inconvenient though it is to admit this, they tend to get discouraged more easily. There are stats showing that women stop searching for software jobs after X rejections, men after Y (on average), and that Y > X. Google found that women were getting promoted less than men simply because they weren't putting themselves forward for promotion as often. That pattern crops up again and again - women hold back when they could push forward.