Like, I REALLY don't care if people simp for underage fictional characters. But, like, keep it to yourself, or put it in private spaces.
It's adults who try to use fiction to justify simping on underage people that bother me, and Oda doesn't do that.
But, if a character is immature, I generally don't simp for them.
I have NO problem with Pudding x Sanji, because I honestly think Pudding is way more mature than Sanji in a lot of ways.
Carrot is clearly still a child on a lot of levels, which is why the idea of Naito wanting to wife her up and make babies with her weirds me out.
There's plenty of people who wish they had found love and had sexual relations when they were younger, and many adults use content like that as a release for their regrets in their own lives. That's fine, it's the stuff where grown men actually want to wife up teenagers that makes me gag.
Go ahead, simp for Carrot, just don't tell me you wish the 15-year-old rabbit girl was real and pregnant with your babies like Naito, OI. Wishing you had a happy, functional relationship in your teenage years is normal. Wanting to do things with a teenage girl half your age as an adult is weird as fuck.