by Doctor Science
I made my post about subtractive masculinity because I was thinking about fan and gamer culture -- and lo and behold, almost as soon as I posted "Gamergate" (which has been boiling along for months) leveled up to get covered by the mainstream press. To cut a very long story extremely short, there's been yet another case of self-labeled "gamers" showing that they disagree with a woman ... by inundating her and anyone associated with her with threats of rape, torture, and murder. 
Subtractive masculinity is why the prospect of women being associated with video games gets such an out-of-control, violent reaction. I think a lot of the males (boys or men) who play these games are getting their sense of masculinity from them, their reassurance that they are Real Men Who Do Manly Things. But because our culture's construction of masculinity is subtractive, when girls or women are publicly seen to do something, that thing becomes unmasculine.
In practice, what this means is a guy can get mocked for it by other guys, told that he is "girly" (and that's the least offensive term that might be used). The only way a guy can protect himself from that kind of teasing (which can escalate all the way from little comments to harassment to actual murder, depending) is to do something girls don't do. And that means either picking something with physical demands few women can meet, or something that girls don't happen to do -- and then keeping them from doing it by any means necessary.
And the reason it's worth that kind of effort is that, in our society, men are the default value of "people": only (white, straight) men automatically have the status of "full human being". In other words, if you're not masculine, you're not *really* a person. That's why guys who feel their masculinity threatened can go into a violent, toxic meltdown -- because loss of personhood feels like an actual, life-or-death existential threat.
So what I think is going on is:
- Boys see that video games are associated with guys, and that the characters in many games are hyper-masculine: super strong and/or violent, with exaggerated muscles and powers.
- Playing these games lets boys (and men) feel as though they, too, are hyper-masculine. This is especially important for guys who aren't stereotypically masculine in physique or actions in real life, guys who don't otherwise conform to a masculine ideal.
- Gaming becomes not just part of their personal identity, but of their identity as *men* -- and that means it supports their identity as full human beings.
- If women get associated with video games, the whole thing will come crashing down. If they can't rely on gaming to demonstrate that they are truly masculine, they don't have anything left -- they risk losing their status as human beings, defined as "people who don't deserve to be tormented". That's their world and experience, after all: only masculine men can escape torment, it's open season on everyone else.
- But though video games *feel* hyper-masculine, they don't actually require any skills at which males have a natural advantage, like physical strength or size. They actual rely on memory, concentration, reaction time, fine motor control, pattern recognition, and planning -- qualities that females share, statistically speaking.
- So the only way to keep girls and women from playing and creating video games is to *keep* them out, to make games that aren't designed to appeal to them, and to torment any ones who are interested nonetheless. To the guys who do this, it doesn't feel as though they're over-reacting about mere games, it feels as though they're defending their right to *exist*, their right to be treated as human beings.
The good news is that this is in fact a case where #notallmen, because boys who can see through patriarchal nonsense and men who've matured emotionally won't act like this. The bad news is that they don't seem to have much traction against the rest of the guys in gaming. What would it take?
 The details are tedious, brutal, and IMHO fundamentally unimportant. The serious issue is that women playing online games, talking about them, or working in the gaming industry can expect crushing levels of harassment, and it gets worse the more public they are. As game developer Brianna Wu said in July, there is no skin thick enough to deal with what they often experience -- and just this week the police told Wu and her family to leave their home because the threats have become so serious.
That's not even the worst (so far): Anita Sarkeesian, a feminist video game analyst, had to cancel plans to speak at Utah State University because of emails threatening "a Montreal Massacre-style" school shooting -- and Utah's open carry laws wouldn't let them keep out people with firearms.
 Hey you lawyers -- is this for real? WTF? How are people supposed to protect themselves against this kind of terrorism? Because it sure looks like terrorism to me.