User blog comment:CNBA3/Chapter 439: Alvarez Empire Prediction/@comment-4164634-20150603190750/@comment-7418318-20150603191433

Fairy Tail might have decided to go to war against Tartaros, but Tartaros were the ones that struck the first blow. The attack on Cube was just the reaction and also an attempt to save Magnolia, though only partially successfull. I seriously can't imagine anyone faulting Fairy Tail for it.

Besides Makarov wasn't particularly remorse- or fearfull after the Phantom Lord arc, where he was much more at fault, so why should he flee in fear now?