I think Zoro would never want to rest when he was taining, but Mihawk would force him to rest, so Perona would take him shopping with her. And after their first shopping trip fiasco, she gave him some rules, like if she picked on another bitch he had to back her up.

And I think Zoro took that with him, so whenever a Nami insults some other b, Zoro is there in the back like

-right -busted -she got yo ass -I would leave if I were you hoe -snatched yo wig -period -on cunt - negative aura

I mean it's their mean of transport, but they also live there.

And one time they paid him to ignore Sanjis comments the whole day, and bet on how many hours it would take for Sanji to ask Zoro if he did something wrong or even apologize.

It took him 2 hours to go and actually ask Zoro if he was feeling bad about something he cooked or said.

I mean, they all went through a lot, but they all knew Luffy suffered the most after what happened to Ace.