The forum and chat room operates separate from each other. If a user want to chat they can go to the chat room, if they do not want to chat they will most likely only spend their time on the forum. Personally I hate when I am on a site and a chat window popups. However when I am in the mood for killing time I will go to the chat section of a site and wait till something happens.
My guess is that most users of this site do not want to chat, hence they do not go to the chat room.
Ideas for new sub forums or any other suggestions on how we can improve and this forum.