Why Aren't There More Female Screenwriters?

So three posts below, where I rambled about not wanting to direct, I had people list their favorite screenwriters, and they did.

Counting everyone that everybody mentioned, there's about 40 names.

And they are all male. Which I didn't even realize, until Amy F. pointed it out in comment #24, and wondered why.

I made some lame response to her about how women are drawn to more relationship tales/serious dramas, and that that's the kind of stuff that usually winds up on TV, but that's obviously not the complete answer (though it's less badly-stereotypical than you might think).

There are a lot of women working in film today, and a lot of high-profile movies have been written by them. Susannah Grant wrote Erin Brockovich and In Her Shoes, Nora Ephron has written a ton of stuff including When Harry Met Sally, Callie Khouri wrote Thelma and Louise and Something to Talk About. Allison Anders has written a lot of stuff, including Gas, Food, Lodging. Sofia Coppola has to be listed, just for Lost In Translation.

I can go on and on, but obviously not that long, because yeah, it's a profession dominated by men. White men. And lists like the one below, of respected screenwriters, tends not to include any -- or many -- women at all.

Speaking from experience, women tend to write "softer" scripts, but not all women do. Hollywood executives seem to be increasingly female, so men hiring men would seem to play less of a role... wouldn't it?

I'm sure there are a slew of reasons that contribute to this imbalance, that I'm barely touching on. Maybe women are much less willing to write genre crap. Maybe it's something genetic.

It's a fascinating imbalance, because on certain levels, it doesn't make all that much sense.

Anyone have thoughts on this inequity? Favorite female screenwriters I haven't mentioned?

And for the aspiring female screenwriters out there, do you worry about this? Does it affect the kind of things you try to write?