"Guys-only" games are a fact of life. Mine is that way and won't ever change, despite possibly being perceived as exclusive or offensive. That's just too bad, from my POV, because we have invited women to join our group in the past. Not just for a single game, mind you, but as continuing members of the group.
The first of them was a great player. She really got into the character she'd created, came up with an appropriate background, read the rules often, role-played entertainingly, and generally added a hell of a lot to the group. I considered her a good friend, too, and the group would go out to play pool, drink some beers, what-have-you. Eventually I figured out that this woman had a thing for me, and was telling other players behind my back that I was making a huge mistake getting married to my fiancee. EXTREMELY awkward. When she moved away, there was great relief (on my part, especially).
The second of them joined the group for two sessions. She spent the entirety of both complaining about how she wasn't outside on such a nice day, if we were going to sit here we might as well drink wine, etc. etc. etc. She wasn't invited for a third game.
The third of them, and her husband, started as great players. But soon it became apparent that the two of them were just going to bicker all session long. When the wife threw a tantrum whose target was my minis, she was asked not to play again.
The fourth, a co-worker, was invited to join the group and seemed excited to do so. She went out and bought a rulebook immediately. In the two months she was a part of the group, she flat-out refused to do the baseline work that any player must do: read the rules & know your character. At the end, she'd never even bothered to complete her character sheet. In an awkward exchange, it was explained to her that we'd given her what we thought was plenty of time to ascend the learning curve, and she just wasn't doing anything at all. We even gave her another session after that, and still no change. So she was asked not to return.
That's my experience with females in our gaming group. Your experience, of course, is different. But I'm heartily sick and tired of reading on gaming boards that I'm a bad person, or offensive, for running a guys-only, "poker night" game.
I love my wife very much. She has no interest in gaming, but if she did I'd certainly work to nurture that. The rest of the women out there can find their own damn gaming group, because I've done my part.
Four times bitten, five shy.