I don't think it's far fetched to believe homosexuality could be a choice for some. People associate with groups for a variety of reasons. For example we just saw in the news a woman who passed herself off as being African American because she related more to that community. Inmates in prison may engage in homosexual behavior while incarcerated then revert back to heterosexual relationships once released. Transgender choose which group they feel more aligned with. 
Policy wise it makes little difference. My point is biology and nurture provide billions of variations. It's no harm to me what gender someone aligns to or how they got there.
If you accept diversity then accept diversity. An individual's spiritual beliefs are another part of diversity. Cliche's rarely hold true. There are people who believe homosexuality is a sin and still do not believe in the persecution of Gay people. Accepting diversity does not mean you have to agree with the behavior.