Same, forums which just specialize in one topic tend to be boring, but they are very useful when you need to know about a lot about one topic like Forum themes, fish, web design, computer repair, etc.
But, I think if a forum have too many sections and don't revolve around one main theme like "entertainments and arts" then it can be kind of unorganized like I been to some forums where people talk about blogging, games, pets, political events, music, and a lot more. It takes forever to find old topics that I want to read, so I usually don't stay long at those forums.
Unless the forum have subforums inside of each section then it be better.