Here's an example of what I mean by misogyny: a previous manager at a company printed out an A3 picture of a woman in hotpants and a bra with the caption "Please update your Jira tickets before you go home". When I came in the next day to replace it with a picture of 4 (clothed but sexualized-I think it was a picture of a male stripper troupe) men, I received a disciplinary action from the company. The same manager, when he introduced me to the team, introduced the male programmers as "he works on ToolName" and the female programmers as "she makes things look pretty".
This is reasonable subtle stuff, but I am surprised (though happy) if you've genuinely never encountered it rather than cultivating obliviousness or growing a thick skin.
e.g. it was a running joke at my last job how women didn't know anything about hardware, but there was a male programmer there who repeatedly used "memory" to mean hard disk space and "hard disk" to mean the case, and nobody ever said anything. And a guy can banter back - this guy's comeback when anyone corrected him was "who'd want to know boring nerd stuff like that" - but a woman quickly gets pegged as sour, bitchy or snooty if she talks back.
And after a while of every dumb slip-up being jumped on, is it any wonder that some women don't leap gleefully into the conversation?
(Plus as female coder I am always happy to talk about programming, retro computing, science fiction or other "geek" topics, but 80% of the Man Chat in my office is about cars and Top Gear, which don't interest me at all.)
Don't get me wrong: very few of the male IT professionals I've known have been openly hostile. But there have been those who have seemed slightly confused by my presence and ignored everything I said, those who regularly met up outside work without asking me and months later said "we would have asked you, but we didn't think you'd be interested", those who say nothing when someone louder insults women...
...and the ones who rush to applaud when a woman insults another woman, which to be honest I found your post rather close to with its implication that any woman who's had a harder time in IT is whiny, antisocial or doesn't "know their shit". (Apologies if this reply just seems to continue that trend. I'm grateful to you for starting this topic, which I've found interesting, at any rate.)
Equally it's probably not very helpful if the distillation of your point is "women ('girls'): have you even tried talking to your peers?". Of course they have, it's the most obvious thing to try. To re-iterate, the problem is not that geeky men and women have strong social cues not to interact at all (like some sort of really weird Victorian tea-party), it's that there is a minority of men are actively and aggressively misogynist and the majority of men who aren't refuse to call them on it. Unfortunately there isn't much that women can directly do to change this (hence the perpetuating problem), they can only highlight this behaviour and expect to be treated with professionalism and decency.