No. If we were to judge the morality of homosexuality on the basis of a person's genetic predisposition, it would only be logical to apply this reasoning towards all behaviors. Some people are believed to be genetically predisposed to being more aggressive which in turn would cause them to be more likely to commit acts of violence.
IF homosexuality is arguably acceptable only the basis its genetic (if it is) then why is not violence likewise arguably acceptable on the basis on genetics? Double standard? I am not comparing homosexuality to violence as a lot of homosexual advocates might over simplify my argument to be, I am saying we must judge acts for themselves, and not look at genetics to justify them. They might say homosexuality is consensual, violence is not, well if that is the case then how is the genetic argument relevant at all in the discussion of morality? It isn't.
Furthermore, if homosexuality should be tolerated or accepted on the basis its between consenting adult, then shouldn't it be acceptable for two consenting adults to give each other narcotics since its consensual, and doesn't harm others? By this reasoning it might be argued incest, self infliction, and suicide should be tolerated or accepted on the basis if a person if only harming himself and not others, or acting with free will and consent.
Finally, why should a sexual act be recognized as acceptable by a society that is disproportionally linked to Sexually Transmitted Diseases, and has no real benefit to society as a whole, except PERHAPS as a sort of population control--removing a number of people from the breeding population. Furthermore, if homosexuality is genetic, shouldn't the open homosexuality with homosexuals refraining from procreating decrease the future homosexual population? This may change though because of things like invitro fertilization.