That Dr Jekyll is homosexual is just one possible construct added on to the story. From what I remember, there is nothing at all in the original story that suggests homosexuality.
Could it be that the story presents the inrreconcilability of the dilemma: if one gives in to desire utterly there is intoxication and corruption; if he chokes himself back, he creates a diseased personality. We are neither animals nor machines and we need to treat ourselves like the humans that we are.
