Just some thoughts on this.
The question of whether or not something hurts a person is not relevant to whether or not a person agrees with it. A person can disagree with something without it hurting them specifically. "How does it affect you or your marriage" is a common but irrelevant challenge to someone saying they disagree or don't support homosexuality.
No wow having said that, I do think there are ways that homosexuality affects all of us. First of all, let me say that the word "choice" here is often misconstrued. I think the word choice makes people think of a person sitting on a couch one day saying, "Hey should I be attracted to opposite sex people or same sex people today." But this is way too simplistic in thinking. I don't think we choose our attractions and feelings. People don't choose to be angry when someone hurts them, they don't choose to be sad when someone dies, they don't choose to be happy when something great happens. Feelings are a natural way of relating to and understanding our world and lives. Similarly, I think attractions aren't chosen, they naturally happen as we look or ways to relate others. But sexual attractions are different in that they address a different and very personal and intimate set of needs.
Why is heterosexual attraction the default? Basic biology can answer that. So where does homosexual attraction fit it? That is the debate. I am not aware of any real evidence that people are "born gay." There are a few theories, most of which have poor supporting evidence. Scientists have agreed there is no "gay gene" or genes. The most compelling theory is probably about people who developed with very irregular hormone levels, and even ambiguous genitalia. But, this would be a very small percentage of people who identify as LGBT. And, this would indicate that irregular hormone levels (and brain studies) show that these identifications would be a result of critical abnormalities, not a gene sequence or a random occurrence of being "born that way." What we do know (and have for many years) is that a very high number of individuals who identify as LGBT were exposed to very significant developmental, social, attachment, and/or emotional challenges. Rape, molestation, severe abuse (and not just sexual), extreme neglect, very poor attachment to parents, and even early sexual experience are a few that greatly contribute to sexual identity or orientation confusion and stress. Unfortunately, due to current political and cultural changes, we have now made it almost impossible for these individuals to work through their trauma and deal with their confusion, which is causing a tremendous amount of psychological and emotional harm to them. "Being molested as a child has nothing to do with your lack of attraction to (or specific attraction to) that gender, you were born that way, accept it." "Being completely neglected by your same sex parent has nothing to do with your need to connect with that gender, you were born that way."
Of course, not everyone suffering from these conditions come to identify as LGBT, but it always has consequences for that individual, including LGBT concerns for some. The "born that way" mantra now prevents many people from being able to truly explore the need we all have for intimate connections and understand how their experiences have helped shape their alternate attractions. They are left to try to satisfy them the best they can, but through the midst of trauma. Now, confusion is being weaved in to childhood and teen years by culture and the confusion element has been increased exponentially.
I don't think people "choose" who they are attracted to to satisfy their intimate needs, but they can clearly choose to act on them or not. As a married man, I have attraction to other women sometimes that I shouldn't act on, and don't. I may not choose that attraction, but I can certainly choose to act on it or not.