In addition to all that you'd need some sort of top down project management structure. If the people who are directing/supervising the project decide one of the sequences that a bunch of people have worked on for 6 months isn't working, they need to be able to make the decision to abandon the work without causing massive animosity and have people quit the project.
I would also imagine "on budget" will trump most quality or artistic issues in this project...
As if these people weren't bogged down working for blender movies, they'd have jobs at Pixar. These people apply to get on the project and they are hand picked crews. They in some cases get to live on the "campus" and work on the film. Everybody benefits, the film is released for free in dozens of file formats / resolutions.
the residual benefits are big, the educational benefits are obvious. Some of the crew have gone on to bigger paid work including pixar and the lego movie, and that's just the popular recent ones. Others create their own companies, others work more on blender and do what they want.
To say it's a waste of talent is very strange way of looking at this.
There is no reason to try to be completely original. There are plenty of great stories out there.
http://www.blenderguru.com/podcast-beorn-leonard-working-on-...
It's a good interview with Beorn Leonard, one of the animators on Sintel, and most recently the Lego movie.