I've been lurking a while on the conversation but I'd like to stop at this for a second.
You're surprised that sexism has been effective in keeping women away?
Just stop on that comment for a second and then realize that this is privilege. You don't have to worry about this kind of thing at all and because you don't it is a symbol of your privilege. You are free from this kind of fear and frustration.
What had been increasing other people's frustration is that what you've been saying though your words is the whole, "I don't see it, ergo it must not exist." When people point it out you still have that hat on your head and there's nothing women comment makers and experience sharers feel that they can do to dislodge it because you're denying their experience.
It is a large problem because the people who are affected by it say it's a big problem. You can't tell people who are experiencing the situation that it's not a big deal because that's making their problems seem invisible.