What is the sense of stereotypes?

What are stereotypes good for? Why do we put people in boxes? Do we learn what is obvious? Why can’t boys wear skirts without instantly being labeled as gay? The movie ‘A Kid Like Jake’ is about parents doing their very best raising a young boy who is different than others. They love their child, but for some people it’s not so easy to accept a boy who seems to them being more like a girl.