Quote fromKinda a cool idea, but hey, DING DING, isn't this game about creating stuff in-game :S?
Damn people are lazy. :3
As far as I can tell the point behind this is creating custom level bases, so instead of having a randomly generated map that you have no control over, you build your own map with this then anyone can build over it. For example, you could build a giant castle and have users modify it in game, or a big city where users can design their own building insides, which would take hundreds of hours to do manually.