I feel like this is the key.
I'm interested in this topic, but I see no good solutions. The best I've seen is the idea of PubRunner, simply because it takes place away from the male-dominated Game Store atmosphere. The issue is that non-CWM don't feel comfortable at game stores currently, by stereotypical representation alone, and it doesn't matter how much effort we make to create a pleasant atmosphere, that stigma of the Game Store as being a 'Guys Only' clubhouse will prevail.
Further, the problem is compounded because of what Luiloth pointed out, both from her own experience and from her best friend's: They feel a pressure to perform, that 'failing' reinforces negative stereotypes. If I could have one wish, it would be that Losing is not seen as a huge negative. I wish that the fear of failure was never a reason to show up to a tournament, but it is, and is a large reason for several people I know, both CWM and not.
One of the other ways to promote diversity is to have a 'Minority Only' tournament or event. The problem is managing to advertise that. The other problem I have with this is that needing to have them at all is a problem. But I feel they're the best actionable solution to the problem. (What I mean by this is that, ideally, we wouldn't even be talking about this, the numbers would be properly proportional, and this sort of outreach would be unnecessary because our normal tournaments look diverse. But they don't, so we do need this sort of outreach.)
Despite being cliche, I don't care who or what you are. If you want to play Netrunner, if this Cyperpunk game looks interesting, or this Asymmetric Customizable Deck game looks interesting, I want you to play it and to have fun. I want my daughter to play once she's old enough to read the cards instead of eating them. I've taught both guys and girls, anyone who's willing to point at the box and say 'Hey, what's that?'
The final thing I can think of to increase diversity is to have more prominent diverse figures. The only non-CWM figures in Netrunner that I can think of for strategic content are Hollis Eacho, Dien Tranh (might be misspelling), and Timmy Wong. I also think of Ran, but that's more because I've met her and spoken with her a bit, she doesn't actually produce much in the way of strategic content. Alexis (who runs the Facebook group) and Leigh (who I've heard on Terminal7 a couple times and wrote a Novella) I also think of, but not for strategic content. Podcasts, tournament wins/placements (again, Ran shows up here as the highest Weyland at Worlds, iirc) or just articles/forum posts here would all help to increase visibility, and I think would contribute to a more welcoming atmosphere.
My feelings on this are complex, but I know that I want this game to be a place where my daughter could go without discomfort, so I'm interested in making that happen.