Good Question and one answer (aspect) is
So they have something to aim for.
From my own experience they are, because they are trying to examine the future use cases and functionality. Without these the software produced today may not be worth much and the wheel reinvented to cover the final goals of the network. Like phone usage.
Its not as if the core developers are spending much time doing this exploration and is one reason why @ben is employed, to get the community (of developers) to be involved in shaping some of the future goals of the software.