it is. see below for more discussion
I certainly didn't choose my sexual orientation. I distinctly remember entering puberty and suddenly finding the girl who lived across the street attractive. I never thought to myself: "hmm, should I find her attractive, or should I be attracted to one of my guy friends?" It just happened.
That's because in a healthy human being heterosexuality is the default. All healthy people are heterosexual
Why would it be different for gays? Did you choose to be heterosexual?
Everyone is born heterosexual. Some trauma happens to some people and they (subconsciously) choose to be homosexual
Assume for the moment that a child is born genetically right handed. Now at the age of two this child has his right hand amputated. He will choose to be left handed after that point and at the age of twenty may not even remember ever being right handed. He was damaged and turned from being naturally right handed to being unnaturally left handed.
Homosexuality works exactly the same. We are all genetically heterosexual but some people become damaged and choose to function unnaturally
I'm not an expert in the science of this area, but have never seen any research that supports the view you expressed. Can you point me to some?