Yeah but the 'You could come join my gang of thieves' / 'That is literally the worst fucking thing I could imagine' misunderstanding is easy to get. Sette is being as nice as she gets, but what she puts on the table is antithetical to Jivi. He lets his mouth run instead of being tactful, neither of them'll back down, boom.
I do think Jivi judges Sette too harshly given how they first met, but Sette's first impression of Jivi was not very correct either. This guy busts out of a slaver gang with a homemade shank, then runs off and says he's gotta do something crazy and hijacks a construct. That's like HELL YEAH Sharte gangster material, but it's not who Jivi is 90% of the time. And probably not really who he wants to be.
Honestly I think both Sette and Jivi have huge self-worth problems stemming from their parents, that should be obvious. But the ways in which they can see themselves as worthy are different, and Jivi has actually taken on a rebellion - pethaps just out of cowardice, or what he perceives as cowardice - that Sette hasn't yet.