Why do people make fun and ridicule those that believe in something that isn't 100% proven?

I believe there a lots of people who feel threatened in some way by the kind of things you mention. They only feel secure when everything is kept just they way they have experienced it. Wouldn't it be nice if we could agree to disagree, politely. Why is it necessary to be rude? Let us consider different ideas and accept or reject them as we wish without feeling somehow defensive about the whole thing.