Why do people ask people not to "label" them?

when in most cases they're obviously dressing and acting in a way that directly centers around a certain group of people. I for one could careless what people said about me because after all is said and done my opinion of myself is the only one that counts. I know I dress "weird" sometimes and people have attempted to pigeon hole me many times but have always come up short in trying to articulate a definition. The reason in which I would be concerned with someone mislabeling me would be if they were talking about my views incorrectly. My opinions are finite and when someone misrepresents my opinions they are misrepresenting the bulk of who I am.