Married people are doing something that is very, very hard -- to combine the lives of a male and female, with all their physical and personality differences, into a stable relationship that persists across time.I started to reply in David's LJ, but it got too long, so it goes here.
When they are able to create children together, married people then provide the role models for those children to learn how to become a man or a woman, and what to expect of their spouse when they themselves marry.
When a heterosexual couple cannot have children, their faithful marriage still affirms, in the eyes of other people's children, the universality of the pattern of marriage.
When a heterosexual couple adopts children who are not their genetic offspring, they affirm the pattern of marriage and generously confer its blessings on children who might otherwise have been deprived of its benefits.
Orson Scott Card is making two assumptions: That children are the property of their parents and that role models for a committed relationship only come in Mother and Father.
The first one, I don't have a problem with. Marriage -- the legal contract -- is about property and inheritance. The reason a child is "illegitimate" is because the legal contract does not include them. Genetics are not as important as the legal documents. "Reproduction" is defined as "when the kid is born", not when they were conceived, or with whom. That's why we have shotgun weddings (eg Ronald Reagan and Nancy). That's why one can adopt. (That's what "born again" originally meant in the tribal culture of Israel.) A "legitimate" child is so because of a piece of paper, not because the signatories contributed DNA.
Fortunately for children and unfortunately for Card's argument, all these legal rights can be conferred through other types of contracts. Heinlein's "line marriages" or gay unions or whatever. Draw up the legal contract and sign. The law has changed in response to the changing culture, and will continue to do so.
As to his second point, "the universality of the pattern of marriage", he seems to be ignoring thousands of years of cultural contra-indicators and, more importantly, sixty years of television programming.
a) The family unit is no guarantee of successfully raising kids. Too many families are dysfunctional and pass their dysfunction to their offspring. Card is assuming that the scion of two people is automatically loved and raised properly, and that's not justified by any historical research. Indeed, it's only in the last few hundred years that the modern concept of the "nuclear family" was the major engine of child-rearing. It takes a village, or at least an extended family. Some kids are raised by their nannies. Even today, many cultures (including some branches of Card's Mormonism) don't believe in the "faithful marriage" model of the family and practice various forms of polygamy.
b) The kinship relationships and sex of those rearing the child are less important than the love imparted. Card is further assuming that love can never exist except under a legal marriage contract. That's foolish on the surface of it: Some kids survive orphanages. And one just has to look at television programs, from Family Affair to The Courtship of Eddie's Father to Bonanza to Buffy the Vampire Slayer to see examples of single-parent families (often with the help of Mr. French or Giles) that raise kids successfully.
If the love exists between two people, then the love will extend to the children. If it doesn't, then it won't. This is not a hard concept.
I am neither in favor nor against the concept of "gay marriages". My "small-l-libertarian" leanings are coming out. My grandmother used to say, "relationships work when both partners contribute 90%" and I see no reason why the two have to be of different sexes or why there only has to be two. Yes, I think a dyad has the potential to be more stable. I'm in favor of a committed monogamous relationship between people who love each other. There are other kinds of committed relationships that work, too.
When it comes to raising kids the more love the better. The greater the knowledge pool of the caregivers, the smarter and more independent will be the child.
Okay, I'm a romantic. Call me a romantic. You know you want to.