Are you implying that nothing should be "banned" at all? There are examples of tons of things that have to be banned to keep the society sane at some level. For examples, things that are considered illegal by the publically elected governments and hence are banned to be shown on the internet or elsewhere or promoted in anyway. What matters more is how are the decisions made whether to ban or allow some content.
In the non-virtual world, there is a publically elected state that makes those decisions. In the virtual world, those decisions are made by private companies that own that part of the virtual world. Ever since the creating of the virtual world, there has been an ongoing tug-of-war between the state and the corporations for this exact control of authority. Now that our virtual and non-virtual worlds are so intertwined with each other, the state is still trying to catch up to understand, contain and secure the virtual world but they are still at loss.
In the non-virtual world, there is a publically elected state that makes those decisions. In the virtual world, those decisions are made by private companies that own that part of the virtual world. Ever since the creating of the virtual world, there has been an ongoing tug-of-war between the state and the corporations for this exact control of authority. Now that our virtual and non-virtual worlds are so intertwined with each other, the state is still trying to catch up to understand, contain and secure the virtual world but they are still at loss.