This story was great fun to listen to! Only the beginning... It just didn't grip me, had to rewind a few times before I started getting into the story. There was just a bit too much unfamiliar information in the first minutes, which needed my full attention. Being who I am, I can never ever give anything my _full_ attention, so I had to rewind over and over because I kept missing words or part of a sentence and then I was completely lost again. To me, the story had a very difficult start and I noticed that more listeners had that problem.
I was, however, very glad that I kept on going! The story was great and interesting. It did touch a few nice anthropologists' issues, issues that would also apply to embedded journalists and such.
As for the aliens, I agree with Bdoomed: a very cool idea, that the young were working so the old can play. What would humanity be like, if we started doing that today? End of humanity, I predict ;P