I think everyone is capable of enjoying sex or learning to enjoy same-sex relationships. I also believe in the sexuality being a spectrum, and we are all born on a certain part of that spectrum, and then slip and slide because of many factors. On different people different factors will have different effects. A poor relationship with either parent will affect each person differently as well, even siblings. Some gays were born with more femine traits, physically or emotionally, and would probably, on average, have a more difficult time relating with their father figure. Then again, some who were probably born predominantly straight might have grown up with an unhealthy relationship with their mother and grow up unable to establish gratifying relationships with women. It's all just a mix of many factors for many people, for other people probably not too many factors. People trying to find the root of it doesn't necessarily lead to or come from a negative view on homosexuality, on the contrary, some straight people who build a better understanding of probable "factors" or "causes" tend to arrive at a more accepting attitude. I agree, all the different degrees of sexuality have their place in our society, evolution has and will determine which ones will be more predominant, and which ones go extinct. We don't only evolve biologically but culturally as well. Humans are so complex, i.e. we are no longer simply driven by survival, hence societies, cultures, groups might go back and forth between acceptance and non-acceptance depending on events that shape them, just as nature selects and deselects, represses and expresses depending on need.