Both, some restricted some not. I think it is important to include both, as various forums are for various people. My intention is not to have a crowded house but decent discussions... I love the variation that the Internet gives us. Another thing you have to remember is that this type of medium is still new for many. Just look at the Scriptkeeper, 15,529 registered users how many of them are joining in a discussion?
Many watchers around and it will take time before this type of service will boom.