My guess is, and I'm not trying to be funny, that they are trying to provide an alternative to Apple/Google/Microsoft. They are also trying to make shed-loads of $ € ¥. They don't strictly have their own OS the way those guys do but they plumb Android to remove everything customer facing from Google (App store, music store, book store, browser, ...). I wish them well because I think that the more competition there is the better off the consumer is. As an open-source advocate I feel that anyone building on top of Android is the open-source model working as it should.