I think it is true that women writers get discouraged in all sorts of way from writing SF, or if they write it because ... well, because they just want to, then discouraged from submitting it to publishers, or from publishing it themselves. Part of it is lack of role models, as you say, Jo, and a lack of recognition (or in some cases respect) for some of the women who break through with award-winning books. (In terms of recognition, it's much the same in fantasy -- with a few exceptions, of course.) And then there is the way that women writers are often treated at conventions or online. And if you stay away because you're made to feel you're not welcome in places where SF writers congregate, then you don't make the connections that might further your career.
I don't think the solution is to make a point of giving more awards to women SF writers, but they should receive the same open-minded consideration, and when they do receive the awards, then they should be treated no differently than the men who have received the same awards in other years, instead of lapsing into obscurity. And successful writers who are in the habit of mentoring new writers, should be more open to mentoring women. Finally, the abusive and harassing behavior that women are too often subjected to at conventions, and elsewhere within the community, should be discouraged by all of us, male and female. It is there, no one is imagining it, and it matters.
And if someone feels moved to post here about how all the above is just being "politically correct" I shall be moved to scream. Loudly. Because I am tired, tired, tired of that same tired argument. It's lazy and self-serving.
Of course you won't hear me scream, but taken it as given.
