@Redx:
Those are just subjective preferences though. Who you like and who you don't like are hardly qualifications for objective evil or anything. The fact that theres no inherent good or bad is even brought up in the manga.
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They're not merely subjective preferences when the story is making me identify with the morals of the main characters and their allies while only portraying their greatest enemies in a purely negative light at least 95% of the time. You can't seriously suggest that somebody who reads Marineford should come out of it thinking that the story is saying Akainu's philosophy of Absolute Justice is an admirable perspective to have. I'm not talking about my preferences, I'm talking about what the story is explicitly trying to make us feel with little-to-no subtlety or open interpretation involved.
One Piece is a series that loves to talk the talk about the complexity of pirates being good or bad people as if it's this huge morally grey series constantly challenging ethical views. Hence those Hannyabal pages and Doflamingo's speeches. But at the end of the day, it almost always portrays Luffy and his allies in an ultimately positive light outside of gags doing things that are compassionate in one way or another. If they do nasty things, it's always either off-panel or before they join up with Luffy. In comparison, the last thing that any of One Piece's defeated main arc villains aside from Arlong and Doflamingo have is any sense of compassion whatsoever.
This is why I love arcs like Jaya, Sabaody Archipelago, Impel Down, or Whole Cake, where Luffy isn't focused on saving another island but more selfish pirate-y endeavors. Yet he's still always a nice person thinking about his friends, his morally positive friends, throughout all of it. Luffy's villains, for the most part, don't really have that kind of versatile depth. They're almost always nasty. Because that's how Oda gets the happy endings he wants. Having a villain that makes you feel sympathetic towards them or raises legitimate ethical issues the heroes can't solve gets in the way of that.
So yes, Oda does like to frame his fights as good versus evil like you said. But the evil side is almost always executed as definitively evil according to the intuitively shared majority perception of society. Oda only really likes to play around with who is "good" and who is really good, but even then it's only to a certain degree because he still wants his fans to look up to and have fun with his main characters.
This is not about who I like in the story, this is about who the story likes in the, well, story.