One Piece's Arlong Park Arc is Aging... Weirdly
A closer look at the Fish-Men's plight in future One Piece arcs makes the Straw Hats seem like the villains in the Arlong Park arc.
When the Straw Hat Pirates brought down Arlong Park, they were in the right. They did it to save their friend Nami and the rest of East Blue. Arlong was a menace, and his reign of terror needed to be stopped. If the Arlong Park arc is viewed in this context, the Straw Hats are the heroes. However, something about this story changes based on the context of future arcs. The Fish-Men and Merfolk are among the most tragic races in One Piece history. They have been the victims of oppression and slavery at the hands of humans for centuries.
Furthermore, contrary to popular belief, they're not too fond of being relegated to living at the bottom of the ocean. Coexistence with humans on the surface has been a long, painful process. Looking at matters like this, the Straw Hats come off as villains in the sense of perpetuating a long cycle of Fish-Man abuse at the hands of humans. The Arlong Pirates are still evil and unforgivable, but the Straw Hats' approach to dealing with them is more insensitive and like a hate crime than intended. The though Arlong Pirates were wrong, it doesn't mean they're thoughts towards humans and their painful experiences aren't valid.
Fish-Man (and Merfolk) Discrimination In the One Piece World
Fish-Men have been discriminated against by humans for centuries. They've been treated as a subspecies of humans who don't deserve any more human rights than actual fish. They have been enslaved, killed, and forced to live at the bottom of the ocean. Some things have changed within the last 200 years, but they still experience widespread suffering. Many of these problems are also shared by the Merfolk. Those living on Fish-Man Island have tried to resolve their problems in two ways. One is the diplomatic route, where they petition and lobby to migrate to the surface. It's a slow and steady progress, but things have moved along a lot since the Straw Hat Pirates visited the island; the royal family even made a rare appearance at the Reverie to discuss this topic.
Unfortunately for the Straw Hats, they've been more familiar with a much crueler solution for ending human discrimination against Fish-Men. It involves the Fish-Men asserting themselves as the dominant, superior species and turning the tables on the humans. The Straw Hats dealt with this reverse racism directly in the form of Hordy Jones during the Fish-Man Island arc. Everybody learned valuable lessons about generational racism and building bridges on that day (except for Hordy and Co.).
The Straw Hats had to deal with Fish-Man reverse racism before Hordy in the form of Arlong. In addition to inspiring Hordy and his horrible actions, he enslaved Nami's home island and killed her mother. He also went on about how Fish-Men were the superior species, and humans were only good for serving their underwater overlords. The Straw Hats fought this Fish-Man to save Nami, so they never had a reason to figure out why he hated humans so much in the first place. This didn't matter back then, but it does change how that part of their voyage can be looked at.
How Fish-Man Discrimination Recontextualizes the Arlong Park Arc
Without the context of human-fish-man discrimination, the Straw Hat Pirates ended up saying some pretty insensitive things about Arlong and his men. Arlong may have been racist toward humans, but it was contextualized by centuries of oppression on his people's end. The Straw Hats only did it because they thought they were being clever.
Sanji might have been the worst offender of the bunch. He commented about the best ways to cook up the Fish-Men and eat them. This is particularly messed up considering Hatchan becoming their friend in the future; Sanji recommended cutting him into thin slices, salting him, and serving him with paprika and olive oil to be eaten as a snack while drinking. The Straw Hat cook also brought up slicing and trimming them, trying them with butter, and turning them into fish sticks. Even the World Nobles aren't known for suggesting the same practical cannibalism as this main character.
As for Zoro, he was bringing out whatever insulting term he could think of. He would call them things like "fish freaks" or "calamari" when the opportunity presented itself. This is to say nothing of all the times the Straw Hats address their enemies as "Fish-Man," "Octopus," or "Fish," which sounds as bad as them being addressed as "human." Fans like to joke about the Pirate Hunter being more of a Minority Hunter, but this was one of his closest moments to realizing the meme.
In fairness, Arlong and his men were the ones who made it a race thing. They wanted to prove how they are naturally stronger than humans. For the human shonen protagonists, this was a chance to prove how far hard work and determination could take them. Unfortunately, the battle shonen aspect of their story also meant throwing around a little trash talk, which aged like cheese.
What Will Happen to the Fish-Men At the End of One Piece?
One Piece is expected to end with the Fish-Men and Merfolk achieving widespread social acceptance. This would mean living freely among humans without fear of slavery or oppression and returning the favor. A few more races in the One Piece world could use this equality, but the Fish-Men have been emphasized most.
Fans have a distinct theory about how this societal change will go before any potential epilogues. The general assumption is that Luffy will destroy the Red Line and, with it. Fish-Man Island underneath. By then, the residents will have boarded the Noah and begun their voyage to the surface. After that, the Fish-Men will take their place as rightful citizens of the surface world.
Once changes are made to accommodate Fish-Men, mistakes like what was said at Arlong Park should become less frequent. Ideally, ordinary humans will learn to be more accepting and sensitive about what they say. Arlong and his men's actions aren't justified, but with any luck, the Straw Hats won't need to beat on any more minorities like them.