Equal opportunity does not mandate equal numbers.
No, but unequal numbers are often a signal that the opportunities are not, in fact, equal. There may be other factors besides gender discrimination, the reasons may be more complex, but the numbers shouldn't be dismissed without an examination of why they are as they are.
The science fiction genre is not exactly flourishing right now. One reason might be because women buy far more books than men do, and because the larger publishing houses (and the big corporations that own them) are no longer so interested in catering to niche markets. Once upon a time, SF could survive by appealing mainly to male readers. This is no longer true. Fortunately, many women do read SF, or the genre would probably be dead by now. Going forward, I think the future of SF is going to be in the hands of the smaller publishing houses, but how many of those will survive in this economy?
Giving the women their fair share of opportunities might broaden the appeal of the genre and keep it thriving. Or ... everyone can sit around and talk about how women are just different from men, poor dears, and see what happens.