One of the reasons why I read OP is that it creates such hatable characters, only to completely tear them down later. It's like a feelgood potion that's bitter on the way down.
I think the best part of seeing the terrible Vinsmokes and the arguably even worse Pudding be such awful people is that, according to what Pudding has said, they're going to destroy each other
I hate that part of OP so much.
There aren't many villains in general that I hate. I'm rarely interested in that emotion when it comes to fiction. I'm always more interested in just understanding the characters, without much in the way of judgement to them. Honestly, I can't even think of villains I actually hate off the top of my head unless it's because of bad writing. And no, it doesn't ever take away from the catharsis of watching their schemes break down. Seeing the protagonist and antagonist given reasons to square off each other is enough. I don't need to personally hate anyone to enjoy that.
It just flat out feels like emotional manipulation. Like, most works just tend to have villains do what they do and the characters hate them, but the presentation that Oda gives is that he's intentionally pushing us, the audience, into a certain corner. That, perhaps more than anything, is why always feel compelled to applaud villains for whatever atrocity they commit. Knowing that the author is pushing me in a certain direction makes me resentful, which then makes me want to be contrarian.
I get the feeling in abstract. It's moral vindication via righteous violence. I feel like I relate to it much more in real life. Like, if someone straight up punched Donald Trump, I'd cheer that on. So I get it. But I just feel that's such a low and base urge to satisfy in fiction, which doesn't work nearly as well BECAUSE it's fiction. Trump is a real life idiot asshole. The Vinsmokes, being fictional, are just puppets made to act a certain way. That just takes all the bite out of the idea for me.