Actually, I see this as the
abandonment of resolution independence. Apple has always been about pixel-perfect graphics, and that's quite hard to do with vector assets. Fonts have to have all sorts of hinting to get single-pixel risers and joins to look decent. That's one of the reasons that fonts are so costly – now imagine that all your graphics require that level of care. Making pixel-perfect "@2x" graphics is much easier.
Then again, maybe those hints are only necessary because of the limitations of low resolution displays. If each pixel is barely large enough to be discerned by the naked eye, single-pixel accuracy may not matter so much. Clearly resolution independence is still desirable for accessibility reasons, even at the end of the pixel density road.
