Being homosexual is no different than being born with Down’s Syndrome, Spina Bifida, cleft pallet etc.
In any case, what normal person would choose to be homosexual if he/she were not?
Who would choose to be addicted to drugs or alcohol? Who chooses to be depressed, suffer from anxiety, or have OCD? Who chooses to have an explosive temper? There are lots of behavior that humans engage in that is unhealthy. Homosexuality is no different, and as a matter of fact, when people seek therapy for homosexuality it has the same recidivism rate as other mental illnesses.