Why sexism is rife in Silicon Valley

I've been maintaining a compilation of articles arguing both sides of this issue -- https://countersearch.net/counter-articles#header-women-in-t... (Articles saying tech has a sexism problem are on the left, articles denying a problem of sexism are on the right). I'm always interested in finding high quality articles for the compilation. But I've flagged this one because is it doesn't anything new and I'm sick of having the same talking points posted to HN over-and-over again.

This article holds rebuttals to some of the arguments frequently made on HN discussions of this topic:

How did we get here? "Well, the research tells us if you hire people who don’t like people, you hire far more men than women."

Not any worse than other industries such as finance? "The gender imbalance is a lot bigger: the top banks are generally 50/50 when it comes to representation; in Silicon Valley, women hold 25% of jobs."

It's a pipeline problem? If it was just a pipeline problem, retention wouldn't be so miserable.