As outsiders, we have no idea what is going on in the mind of the company's bosses, or in Steve Jobs' head, but there is a possibility this money is being saved and built to make a crushing move toward some form or independence in terms of production of materials. Or it can be used to conquer adjacent industries that play into Apple's future moves. Apple has created and filled a new computing market in the last few years; they have eyes on television/video steaming; they know there are expanding markets other companies aren't taking seriously at this point--I'm certain Apple is going for a big move within the next years, and it will have the possibility to expand the company and the company's impact of more than just the computing market.
For evidence, I point to the new building they are going to put in Cupertino.
For evidence, I point to the new building they are going to put in Cupertino.