Using your own example:

Before the iPhone, you had seperate: GPS Camera Flashlight MP3 Player and many other things

With the iPhone, you got all of these and a nice compact package that you could carry with you at all times. Thats not to say feature creep can't be a problem, but more that sticking to hard and fast rules like 'do one thing but do that well' is largely an oversimplification of the world to make the world more comprehendible to those that don't want to look at the real nuance of products/markets etc.