Whether or not it's fun doesn't isn't the primary driving factor in its continued popularity. People use it because other people use it. It got big and now has a network effect of inertia holding it in place until something else takes off and replaces it.
Because there's a certain group of people who feel the same way as you do. And maybe people who read HN are more likely to belong in this group. But HN is not representative of the world.
