because people are assholes and judge before knowing a person. One of my friends weak only black, shows off her boobs 24-7, listen to rock, reads anime, last year she wore a fox tail all year. At first I found her terrifying but now i'm really good friends with her! People just gotta stop judging so much in my opinion :) its them, not you ! ;)
You will meet more people and they will accept you more. Don't get upset, everyone is an individual and entitled to wear what they want. As people get used to your image they will start to listen to your personality.
Depends how you wear it. I love to wear flannels with my Timberlands and a beanie and that's also not really in-line ofcourse, but I have a lot of friends and people don't really care how I dress and what my hobbies are. If you wear it as just a style and not your personality, people look past it. It's more that people who like to dress alternative also have a different face expression (little bit more tough y'know). If you just smile and look like you're open to people, people won't care what you wear.