One of reddit's strengths is that you could build a community within reddit, reusing existing resources and users. Its like an incubator for user-created forums.
Compared to building and managing a forum, reddit provides much easier ways to create a community.
I _dont_ want my social identities linked together.
Maybe I’m the odd one, but I’m constantly making new reddit accounts. I always just generate a random username and a random password, that I don’t store because I just don’t care or want to. I have different logins for all my devices because I don’t want people associating my reddit account with my personal blog and so on.