Why are people still so obsessed with how a woman is suppose to dress and behave...its 2011 now not 1800?

women are been told to work and do the same as men, but are still been looked down on by men and other women on how they dress..etc. example: went out for a drink with a mate i wore a dress it wasn't reveling but still 2 cheeky men tried chatting me up and one of them said "you don't come out drinking dressed like that, your on the pull" lol to my reply was " **** mate ive got a boyfriend and i'll dress how i want to"