lots of people are rude about fat people, e.g. wearing shorts, because they have a mortal fear of being fat themselves and become unaturally obsessed with fat people and what they wear/do
I also find that people who don't wear certain things because they worry what they look like get unreasonably annoyed when others don't care and wear what they like...again, it's their own insecurities coming out. It's not nice I know (and I am highly guilty of not wearing lots of things because I am so self-conscious) but ask yourselves, why are some people so bothered what others wear? I'd say that most of the time that reveals a lot more about those people's own particular hang ups.
i.e. wear what you like girls, especially in the hot weather. (and I will try to practise what I preach )