Actually, studies specifically aimed at measuring tech jobs indicate preferences favoring women candidates: https://news.ycombinator.com/item?id=25069644
People frequently compare the rates of women in tech relative to the general population, not the pool of tech workers. This is misleading, when in fact most companies are quite balanced in terms of gender representation - relative to the representation of women in the field. 80% of nurses being women isn't a sign of men being disadvantaged any more than 80% of coders being men.
That's, perhaps, a systemic disadvantage mothers suffer. Tilting the tables advantages childless women most of all (and would be illegal discrimination against men, were the law to be enforced). Similar to how Ivies' affirmative action helps the children of African despots more than disadvantaged Americans.
As just one example, women still do the majority of child rearing, especially babies. People who want children make that choice, but men typically take a few weeks out of their career whereas women take months or more. That's a systemic disadvantage women suffer.