Well, as I remember the story, the original fundamental goal of the project was to teach kids critical thinking and self-directed learning by giving them a computer they could easily tinker with and reprogram. You were supposed to be able to push a button and see the source code for every piece of software on the thing. I think they were also using a lot of Python (or some other scripting language) so that it would be easy to experiment with the code.
First, the view source button didn't work when it shipped. When they later started offering XP it really drove home that they had abandoned the critical thinking goal, and had decided to just sell fancy ebook readers.
So originally the goal was to empower a portion of the recipients to make their world better. Now, the goal is to stay relevant.