Imagine being born with the hardware of a guy and the software of a girl? Or the reverse? Stuck in a body with which you simply cannot relate. How would YOU deal with that?
I don't know how often that happens or why but we are born to be whom we are. If you must lay blame then blame it on the sperm and the egg. The result had no say in it at all whatsoever.
Yet it is and always will be an issue. Why? Because some folks have no way of feeling special on their own so they must attack "others" as being less than. So because they are so desperate to be "better than" they will grab on to anything. Skin color. Religion. Politics. Lifestyle. Pathetic aren't they?