While Julia hates the society in which she lives, she essentially accepts, almost treating it like a thing of nature. She isn't a revolutionary at heart. Instead, she just wants to do what she wants to do, to enjoy life, and to go along without trouble. She doesn't really question the Party's principles or dispute a lot of what it does; she just wants to have sex and a good time. This is due in part to her youth. She doesn't really remember a time before the Party, at least on an emotional level. Winston, by contrast, is older, and so is bothered by the Party on both a conceptual and ethical level. He knows the society is wrong, and that some of the things they claim are true are really false. This makes him a revolutionary and social critic, even if he's not particularly skilled at either action.