One cannot simply escape the influence of 4chan by not going there. It is a cesspool, and the memes that breed there spread elsewhere. Do you think the players of Habbo wanted the influence of /b? And the violent culture there was shared by meankids.org when they started to frighten Kathy Sierra -- it was only a short jump from there to the death threats, and now they've inflicted harm. She will never be the same.
Freedom of speech guarantees that you will hear things you are offended by. There are some people who think they deserve to live in a world where they are never offended by anything, where everything is Serious Business. 4chan exists to demonstrate how futile and ludicrous people like that are, and appropriately enough those same people are the ones who are most offended by 4chan.
