The one who said that isn't wrong and I believe it to be true for basically any subset of people you can imagine (e.g. people with certain interests, people from certain areas of the world, people with a certain colour of skin, etc.). Your behaviour (or in this context apparently more relevant, your wardrobe) may change or affirm other people's ideas or prejudices of the subset you recognisably belong to. There's no denying that the whole 'T* community' (many think we're all the same anyway) has something of an image problem. People think we're somewhat odd at best (probably justified) and totally disgusting and offensive at worst. The question remains however how effective a single member or even quite a few members of that group can be when it comes to changing and especially improving these ideas.
