(1) Most people ARE NOT born homosexual...There is NO scientific proof to support this claim...Homosexuality is a result of multiple factors that are not well understood...If people were born gay, then 100% of identical twins will be gay, because they share the same exact genes...but we know that is NOT the case...
(2) Morality is NOT objective...It is based on emotions and social consensus...There is ABSOLUTELY nothing in this world that is morally right or wrong...Therefore, engaging in homosexual activity is NOT morally right or wrong, since morality itself doesn't exist in the grand scheme of the universe...It is strictly a human practice...
Something that is "morally wrong" can benefit a large number of people...For example, more people have benefited from slavery than the amount of black people that were harmed...350 Million Americans today are still benefiting from the slave trade...Having almost free labour for over 200 years is priceless for profits...
Another example, if we euthanized all the children born with debilitating diseases, because they will never be productive in society, and all the old people with dementia, and young people who are unable to function in society because of disease (mental and/or physical), we would save a lot in health care costs, and society will greatly benefit and become more efficient...
On the flip side, if we adopted a more communal philosophy in our societies, and equitably shared all our resources then we might just eradicate poverty...If this is "morally good" then why are we capitalists...?
Conclusion,
No one is born gay...People chose to engage in homosexual activities...Just because you have desires to have sex with a man, it doesn't make you gay...Just like you are not a murderer, just because you are thinking of killing somebody...You have to make the choice to commit the act and do it...
Choosing to engage in homosexual activities is not immoral, because morality is SUBJECTIVE...You can't scientifically prove any actions to be moral or immoral....