1) I do not oppose gay marriage rights to genetic gays, if they exist.
2) But a significant fraction of today's gays are acquired gays. It may be a conscious choice. OR, as is more often the case, it may be due to disturbing environmental circumstances that change them into gays.This statement is supported by this wiki page in the following text:
Overall, the environment shared by twins (including familial and societal attitudes) explained 0-17% of the choice of sexual partner, genetic factors 18-39% and the unique environment 61-66%. The individual's unique environment includes, for example, circumstances during pregnancy and childbirth, physical and psychological trauma (e.g., accidents, violence, and disease), peer groups, and sexual experiences. [...] In men, genetic effects explained .34–.39 of the variance, the shared environment .00, and the individual-specific environment .61–.66 of the variance. Corresponding estimates among women were .18–.19 for genetic factors, .16–.17 for shared environmental, and 64–.66 for unique environmental factors.
(Journal references are also available if you still suspect the claim)
This much having been made clear at the outset, I make my case for why I oppose legalisation of gay marraiges when it is not genetic (as is the case with a majority):
No matter how sophisticated and evolved we may be, there are the natural/inherent traits in us and the acquired. When gayness is an acquired trait, it is a mental imbalance, arising from disturbing environmental circumstances. Like with a person wishing to commit suicide or a person who turns a serial killer. In the latter two cases, what we do as concerned citizens is to try and counsel them and get to the root of what factors are causing them to behave in this unnatural way. While serial killers are punished first, to immediately restrained them, they are also later counseled and studied. Yet in the case of gays, some people are arguing to let them suffer the imbalanced state and not trying to address the problem. (If you say gays are happy doing gay acts, and it is not a disease, serial killers are also in a similar perverse state of mind where they are happy after they commit that particular crime which their disordered mental state thinks pleasurable. But neither is behaving in keeping with the natural order of things. That is why they are both forms of mental imbalance). So the right thing to do would be to counsel gays and try to get to the root of what environmental factors are causing them to behave this way, rather than encourage them to continue in their disordered state by sanctioning marriage and other demands they may eventually make. As for the liberty argument, which states that serial killers cause societal harm whereas gays do not and hence must be allowed to do what they please, it is just that the former is obvious physical harm whereas the latter is pernicious mental harm, to themselves and to those around them. For instance, it is not the natural state for a child to be reared by two males. And at the level of infant psychology, instinct dominates over the liberal reasoning and tolerance capacity that adults have. This would thus result in unhealthy children. A similar example to gayness would be why drugs are made illegal in many countries. Although the physical harm might only be to the individual, there is pernicious mental suffering caused to those around him. Or for that matter, why sodomy is illegal in many countries. Sodomy is a good example. It may be a private and consensual act but sanctioning sodomy is sanctioning that disorderly state of mind that the concerned individuals might acquire that could eventually lead to an unhealthy set of moral values which can lead to instability in society if the practice becomes widespread.
I encourage rational discussion.