1. 1080p is the max for HDTV currently and 4k won't become commonplace for a several more years at least
2. Diminishing returns. The jump from 480p to 720p is huge. 720p to 1080p is also huge, but you need bigger displays to see the difference. 1080p to 4k will need much larger displays than we currently have to appreciate the extra detail.
My point is, if 1080p/60 is common next gen, that's pretty much as good as it gets for current HDTV/sizes/viewing distance.
Its good for both camps. Consoles will mostly be connected to 1080p HDTVs for their lifetime nd so this level of power seems well suited. PC gamers are already using higher res monitors and will move to 4k more quickly. They can leverage the additional power to properly utilise their screens