Why do Darwinian arguments always focus exclusively on the individual? We don't live in a vacuum, and neither did our ancestors. Societies must be equally fit or individuals will not survive. Perhaps the gays are a force that makes society stronger. It makes a lot of sense to me that it's good to have a small part of the population who is unemcumbered by the need to care for children and are, therefore, able to attend to other matters.
Not sure I completely follow your line of thought, but if Darwinians focus on the individual it is because individuals drive evolution within a population. As in, an entire species just doesn't evolve. Individuals drive that process over a very long period of time within communities, which makes sense when one considers the wide degree of variations within species.
What I'm saying is that it's not only individuals who are in competition mode. Even hunter gatherers didn't walk around solo. They lived in bands. Societies must be fit as well or they will be a victim to inter tribal competition. I'm suggesting that having the gays around may make for a more competitve society.
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