Where did the nice pirates come from? Did I miss something?
All the people complaining should just stop reading the manga. There are plenty of other manga out there if you just want to read people killing each other with a grimdark atmosphere. The author doesn't owe you anything and won't change the story just because you whine, you know? It just shows you totally missed ALL the actual themes and messages of the earlier part of the manga. Newsflash, it was always about pacifism and finding peace (inner and external).