Well I am wearing what I want. But I still value the advice of other people. Because without input from you guys I may never discover things that are unknown to me but can make a huge difference if taught to me by other people like you guys here.
Society. I think it's an inevitable outcome of human interaction. Probably serves some purpose. I'm with you on the "wear what you want" sentiment, but be aware that how others perceive you will, consciously or unconsciously, impact how they interact with you.