> When I studied CS and electrical engineering we started with 120 students... 15 students made it in regular time
That sounds like a shockingly badly organised course with many barriers to success. Such barriers to success are likely to fall harder on women and minorities (who are more likely to have caring duties, less support in their social network, and will face general discrimination).
With even the facts you have given, it would be unsurprising to me that disproportionately few women bother to apply: even ridiculously fewer women start than on a typical course.
I would be embarrassed if I were an educator or organiser for that course.
> Would you also think that nurses discriminate against men?
No. Although this is not directly analogous to anything I have said, I am giving a good faith answer. I think that nursing is an underpaid profession because it is seen as women's work - just as caring work is often unpaid. I'm not aware that men face significant barriers when they choose to enter nursing.
The careers in which men are over-represented and women are under-represented tend to be highly-paid and/or prestige jobs. So, that's quite a different situation and points to societal discrimination by gender against women.
Computer Science as an industry is relevant here in that: women were initially over-represented, until it came to be seen as a prestige career and started garnering higher pay, and now they are increasingly under-represented.