Distraction from original story.
When do you think that Masashi Kishimoto got distracted from the theme of the Naruto manga and story? Well for me it is war arc. When Obito and Madara were controlling Juubi (ten tails). At that moment, Allied Shinobi Force should have performed well enough in beating Obito And Madara (not killing them though). Then there should have been a ninja fight (rather than a god-like fight), and then story should have continued in that fashion.
Why do I think that it was a distraction? Well because Naruto wanted to bring peace, and what's better to bring it along with whole world? At the moment only Naruto and Sasuke are the ones in power, so even if they bring peace, wouldn't it make them over-power and maybe world fears them which can lead to a plot-hole?