Criticisms about representations of gender (or race and other diversity) are often countered in fandom by sociological or scientific analyses attempting to explain why the inequality happens according to the internal logic of the fictional world. As though there is any real reason that anything happens in a story except that someone chose to write it that way.
Fiction is not Darwinian: It contains no impartial process of evolution that dispassionately produces the events of a fictional universe. Fiction is miraculously, fundamentally Creationist. When we make worlds, we become gods. And gods are responsible for the things they create, particularly when they create them in their own image.
Laura Hudson writes about the shotage of women characters in Star Wars fore Wired.com in her article “Leia is not enough: Star Wars and the woman problem in Hollywood.”
“Science fiction in particular has always offered a vision of the world not myopically limited by the world as it exists, but liberated by the power of imagination. Perhaps more than any genre of storytelling, it has no excuse to exclude women for so-called practical reasons — especially when it has every reason to imagine a world where they are just as heroic, exceptional, and well-represented as men.”