You know a group who must be terribly marginalised? Asexuals. I never even knew there were such a large group of people defining themselves this way till I ran into a young guy who did on a religious website (he's an agnostic). He said he was a Non-Romantic Asexual, in that he didn't desire a close personal marriage like relationship with one particular person. But he went on to explain that there were romantic asexuals who did desire a one on one relationship, but who had no desire to behave sexually within that relationship.
There is a young couple in this clip who seem to fit that category but who at the end of the clip admit to beginning experimenting. So it's obviously very confusing even for the people involved. . Now I like to think of myself as pretty open minded on sexual matters, but I know it took me a lot of assimilating to do away with some assumptions like "suppressing homosexual urges much" and "oh he's just geeky looking and can't get any."
I now really do believe there are probably quite a few asexual people - as opposed to eternally choosing to be celibate people - among us. In fact it may be a lot more commonplace than we know. I suspect the derision and disbelief they face in being open about a lack of sexual feelings for anyone or anything is a big deterrent to coming out.
Asexuality in animal populations is pretty well documented. But we haven't done a hell of a lot of study on the phenomenon in people. Most Psychologists are still arguing over whether or not it exists or if it is a masking of the person's true sexuality due to some other factor. (childhood trauma/homophobic family background - all the usual suspects.)http://www.youtube.com/watch?v=CeKGOMUVU7g