SF is driven by an underlying dream, and part of that dream is profoundly hostile to domesticity, which is traditionally assigned to women. It is hostile to staying at home on Earth. It dreams, Peter Pan-like, of magic flights to a Neverneverland in the stars, full of pirates and mermaids and Indians. It is largely a land of and for Boys. Women love it too, perhaps because they also want to escape domesticity.
These days women's place in fantasy is not as Wendy. Women get to be guys now. They have a place in the SF dream, most usually toting guns or swords. I guess it's fun for women to shoot people , and men certainly feel more at home with women who act like the rest of their buddies. I would say that the dream is hostile to the traditional place of women's power: home. Home is what you escape and Mother is who you hate. Can our stories only glance at child rearing, washing the dishes, building everyday relationships, and earning a living and not exclude women, at least to an extent?
An interesting discussion ensues, with many of the commenters taking Ryman to task (in a thoughtful and civil manner) for over-generalizations and faulty logic. None of them, however-- perhaps because of the larger definitional implications of Ryman's argument--seem to have taken the obvious step of reviewing the Hugo nominees to see if they bear out Ryman's thesis. They do not. I've only read one of the best novel nominees, and there are four short fiction nominees that I haven't yet read, but of the stories I have read--all of them written by men--an overwhelming majority are concerned with domestic matters.
In Paul Melko's "The Walls of the Universe", the driving force behind both protagonists' action is the desire to return home, to their bucolic farm boy childhood. The protagonist of William Shunn's "Inclination" may leave home at the end of the story, but he does so out of a desire to find his mother, and with her the sense of family and belonging that has been missing from his life. In Paolo Bacigalupi's "Yellow Card Man", the protagonist has lost his home and family, and strives desperately to gain a new one. Michael F. Flynn's "Dawn, Sunset and the Colors of the Earth" is made up entirely of domestic scenes--philandering wives, bereaved mothers, closeted gay men all dealing with the disappearance of their loved ones. Ian McDonald's "The Djinn's Wife" is about the dissolution of a marriage (Niall Harrison even described it as a soap opera), and while it may not to be fair to use Ryman to rebut his own theory, his "Pol Pot's Beautiful Daughter" is about a girl finding love and inner peace. There's a little more pizazz in the short story nominees, but even here the domestic is never far away. In Tim Pratt's "Impossible Dreams", a lonely guy meets a cute girl and bonds with her over a shared love of movies. Robert Reed's "Eight Episodes" is about a message from aliens, but that message turns out to be 'there's nothing out there; stay home and kiss your children.' Bruce McAllister's "Kin" comes closest to the boy's-own-adventure kind of SF that Ryman claims we are regressing towards--in it, a human boy gains the admiration of a powerful, dangerous alien, finally becoming his heir. The impetus driving the boy's actions, however, is his desire to see his family made whole, and the story ends by concluding that, for a while at least, none of the alien's gifts, nor the promise of the life of space-faring adventure that he bequeaths the boy, are as meaningful to him as "five rooms in the northeast sector of the city, a better job for his mother, better care for his father’s autoimmunities, more technical education for the boy, and all the food and clothes they needed."
I still think my theory makes the most sense: the Hugo voters, men and women alike, voted for familiar names. This is by no means the first time a Hugo ballot has been biased towards past nominees and winners, nor, for that matter, the first time that it's been dominated by men. This year's ballot is unique only in that it is such an extreme example of both tendencies, as well as in its overall high quality.