Defend everything and you defend nothing.
Still, it's not for nothing that Apple went selling iPhones instead of iPods. They saw that eventually, smartphones have the possibility to become successful in both calling, portable audio/video, photography and even more and combined features (like photo-tagging using GPS).
Although I agree with you that at the moment, most phones suck at all things (exceptions for some phones that have a decent camera, but lack a nice audioplayer, or the other way around).
For instance, my brand new Nokia 5800 has a good battery life, but even my old N70 made better pictures