Freedom. They're certainly free to have a "marriage" ceremony, to share in a mortgage, to share their lives and celebrate in any way they choose. This has been a mantra of mine for some time on this issue - that there are no "rights" lost by not being allowed to marry someone of the same gender.
However, a marriage license/certificate does carry with it some modest amount of perks, benefits, eases in the legal status of life. It does this because of the gain society gets out of stable, opposite gender married couples. Long before Christianity had a hold on Rome, the Romans stopped recognizing homosexual relationships as acceptable. Even when they were acceptable, it was only acceptable from the point of view of the rich male citizen being the aggressor (so to speak), and slaves, women, and young boys being the receiver. It was NOT acceptable, even then, for a male citizen to be the more passive person in a male homosexual relationship - HE would be shunned. For thousands of years, marriage has been acceptable and recognized as a stabilizing force when between one man and one woman. Our laws simply reward that stabilizing factor on society.
Because, truely, what would then stop an equal rights concept for polygamy? For consenting age incest? I won't get into cross-species, because even I think that takes it too far. But, there is no justifiable reason to stop polygamy if you accept same gendered relationships as having an equal positive influence on society as opposite gendered relationships. Can't have healthy kids through incest? Well, you can't through homosexuality, either.
The definition of marriage as being anything but between a man and a woman didn't change until about 30 or so years ago. For centuries before that, there was but one standard. The statistically accurate amount of homosexuals in society is around 2% (about 3% male, about 1-2% female) from credible studies (not Kinsey, who was horribly skewed in his subject pool). A study done by a lesbian to prove the opposite of what I'm about to say found out that only about 26% of homosexuals believe monogamy is important in a relationship. So, 26% of 2% is about 0.5% of the population has any vested interest in changing the definition of a word and getting tax benefits from something that has been a non-stabilizing factor in society for centuries. It just makes no sense at all from any angle (and note, "God said dem fags are bad" and all that crap has nothing, absolutely NOTHING to do with my feelings or argument)
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