There's something of a stigma associated with self-publishing. People have this idea that if you didn't go through the rigorous selection process involved in having someone else publish you, then your work is no good. So why do people do it?
If you're writing for a niche, self-publishing is often the way to go. Professional publishers often look for books that they think will sell several thousand copies in bookstores across America. If they think your book will only sell a few thousand, or even just a few hundred, they will pass you up. Oz is considered to be very niche, so it is very hard for Oz writers to get published traditionally.
Other writers may self-publish simply for the joy of seeing their name in print. This is largely where we get our concept of "vanity presses."
Self-publishing is increasingly common in the RPG sector. This is largely due to the niche nature of the industry, as companies focus on providing support for their existing successful products instead of taking risks on new properties. Also, many publishers are gamers and game designers who started their companies in order to get their babies published and everything else is secondary.
So now that I am a publisher, what am I going to do with it? Will I keep this godly power to myself? Or will I use my powers for good and help some other guy get his work out there?
I don't know. I don't know if I'm going to be successful. If I can't pick a winner that I've created, I'm certainly not going to take a risk on something that someone else sends me. Once I've got a success or two under my belt, we'll see.