The printing humans bit is basically the same thing as the long held belief of "futurists" that the best way to colonize the galaxy is with self replicating robots. Colonize planets in all direction, make a factory to make more, etc. You end up colonizing the universe in a sphere at roughly the speed of light (apparently?) At least this is what Michio Kaku said.
Being able to make the robots human is an added bonus
