I guess its just the way humans are made, i mean, no one is perfect and everyone should be treated equally, and sometimes people accept that and just get along with things, but there are always some that want to get their way, not nessecarily because they're horrible and they are just stubborn, but sometimes they want to make a change and make things better, whatever "better" is..
What im saying is that its human nature to reject somethings, whether is colour of skin, sexuallity, clothes, hair colour or even weight. And although some people aren't as stubborn as others and accept things easily, the ones who dont accept, usually stand out.
If you get what im saying.