Why are some people so narrowminded and stare at punks, goths, emos, mods etc?

I have a mohawk, I wear skinny jeans or homemade pants, studded belts, chokers, band shirts, army camo jackets, fishtail parkas, and customized suits and people stare or talk about me behind my back. it does not offend me, but I really wonder why people think its justified. But, no one does this when I'm with my friends, who are are like this. People like me make change in society- people who are different. So, people say its only a stage, but wouldnt preps and jocks just be a stage? Its all bs.