Bogotanian
Yoshpet
Bogotanian
In terms of reproduction, homosexuality is not a beneficial mutation. Minus the modern world with artificial methods, historically it has not helped reproduction. I mentioned your other point about breeding out of control a while back in another thread. Perhaps a "beneficial" aspect to homosexuality historically has been population control and culling off certain members to ensure that other members survive and get more resources. I guess that had some implications so I was called a bigot for saying that. Homosexuality could be a form of population control, which would make it beneficial for everyone else, but not for the people and animals that are culling off and (historically) have not been able to reproduce.
Occurrences of homosexuality do not impede population growth in a significant way. The problem you suggest homosexuality poses is an artificial one, based on your preconceptions of how organisms are supposed to behave. You may as well suggest that the development of rationality and abstract thought are harmful mutations as they allow us to make choices like abstinence from sex, or invent and utilize contraceptives. This is just a weak argument altogether.
You said yourself that breeding out of control is not a beneficial trait, and historically homosexuals have been an answer to this, implying that homosexuality prevented breeding out of control. I am sure that heterosexual animals were supposed to reproduce to spread their genes, hence why the p***s and v****a were meant to connect. I was just taking the argument you presented to its logical conclusion, that homosexuality acted in the past as a form of population control. But again, what is beneficial to others isn't necessarily beneficial to some. It may be beneficial to a robber to steal from someone (he gets more money) but it's at the expense of the robbed person.
That's a very poor analogy - for one thing, there is a clear victim in your scenario. In the case of gay marriage and homosexuality in general, there is no victim. It literally does not effect non-homosexual people in any way. Even heterosexual couples sometimes choose not to have children or are unable to, and there is no repercussions for such things in anyway, except for how it effects their lives, personally.
Homosexual disinterest in or inability to have children (which isn't a thing, but assuming it is based on basic, non technologically assisted reproduction) would only be a problem if the human race was dying out, and a vast majority of the remaining human population were homosexual. This isn't the case, has never been the case, and never (speaking logically, ignoring extreme, unlikely and illogical hypothetical) will be the case.