Why is there no perfect phone in the One series?
Why is there no true flagship device? Sure, "it'd result in a drop in demand for the other devices though". If they released a true flagship at a much higher price point, would people mind that much? I mean, Apple with the iPhone do one phone (albeit different storage size choices and colour), it has all the features that a current iPhone can have, easy choice. Yet none of the One series is the 'One' that can actually do everything you'd expect a 2012 smartphone to do.
They did cost more than other phones though, and SE lost their dominance with the move to the smartphone platforms.