Anjin Anhut's concise explanation of why gender representation sucks in games and geeky movies (see this and especially this) sounds solid -- if depressingly entrenched -- to me. Anhut's thesis is that entrenched sexism created a situation in which marketing was tilted towards men, and then market research showed that men were the majority consumers of geek culture (surprise, surprise), which led to an even greater male bias in marketing, and more research showing that men were the major customers for games and geeky movies -- lather, rinse, repeat. It's a disheartening tale of how gender bias emerges naturally out of a series of "rational" commercial decisions that reinforce their own flawed logic at each turn.
The thing is, that sales data shows how women responded to geek related marketing, but not why. Excluding and exploiting women, so you can sell more stuff to men, while it might be financially sensible, is a social outrage. This systemic grand scale reinforcement of gender segregation and sexism would only be justifiable, if there would be something inherent to women, that makes them like geek media less than men do. …if there would be some truth to the sexist ideas, which are perpetuated here.
There never was a moment in the history of geek media, when geek media was advertised equally to men and women and there never was a moment in the history of geek media, when it was equally culturally acceptable to be interested in geek stuff for men and women.
Women never ever got as much marketing attention as men have and women always have been treated as an oddity in geek culture, with all the barriers that come with that. There never was a time, when toy cars and robots and construction toys have been made equally accessible to little boys and girls. The same goes for safe spaces and tech education.