User blog comment:IamJakuhoRaikoben/Chapter 450: Alone in all the World, Review./@comment-5268982-20150901161817/@comment-153.91.238.254-20150903041956

Yea but gotta remember that zeref mentioned the same thing and pointed out that if acnologia wanted to he could take over the world at anytime with his power if he felt like it. So that kinda suggests that acnologia has deeper motives than to just destroy everything. He might be waiting for something or he might have something even bigger planned.