Good open source projects are projects, which are made up of code and people. I've never cared for the idea that a project belongs to one person on github.
Projects start out as one person messing with code. Of course the project belongs to one person at that point. As more people join in you can re-structure the project into an organization with multiple owners.
Check out the announcement from June 2010 https://github.com/blog/674-introducing-organizations