I find, at least nine times out of ten, an act of discrimination is fueled by fear. In this case, and in many cases like it, the fear that conservative, Christian-minded individuals have about the idea of themselves, or others, going to "Hell" for doing something a closed-minded upbringing writes up as a "sin". And some of them take it one step further, and assume that if they think one small aspect of public life has been affected in the aforementioned way, then /obviously/, their children, and the children of other like-minded individuals will grow up, possibly wanting to experiment with life in the shoes of the opposite sex/gender.
And, oh my god! They may be right! Because if all the laws in our day-to-day lives actually /did/ work out to be that much more accepting of these sort of things, and people really didn't express such enormous bigotry towards those they perceive as "different", then they wouldn't be so inclined to drive themselves away from even the most playful of thoughts on the matter.
Like the idea that if homophobia didn't exist, straight men wouldn't be so damned afraid of being more (publicly) emotionally involved with their guy friends. I understand that last one has many levels of reasoning behind it. But you get where I'm coming from.
Chris.