I'm not sure what led you to this conclusion and perhaps my perspective here is off but one thing I can say for certain - is that I, along with many other people, love Durance. He was absolutely meant to be abrasive. However, he goes through tremendous growth and rather than word vomit the change he is undergoing, he keeps it relatively to himself. You pick up on it but it's because of subtleties, not because he has 12 minutes of monologuing about why he's changed. He's insightful, crass, doesn't give two ****s about your feelings, or anyone else' for that matter, and calls it like he see's it. He also understands exactly who and what he is and from all accounts, he's incredibly self-aware. You have to keep in mind that he's also seen some ****. Which is probably why he's so abrasive in the first place. This is a priest that killed a god. You have to wonder how that would effect his own faith- the gods in general go from seemingly omnipotent entities that people devote themselves to, prostrate themselves for, and spend their entire lives trying to appease, to little more than the mortals they rule over very very quickly. Compound that with what he learns at the end of the game and you've got a real good recipe for crazy. Everything he dedicated his entire life for, committed deicide for, turns out to be a lie. Not only that, after he engaged in what he thought was the holiest of acts, his goddess cast him aside like a piece of used furniture at the local dump. IMO he's also pretty hilarious at times and offers a comical, if not dark, perspective at times.
Perhaps that's just my 40 year-old disabled combat veteran self finding him somewhat relatable but Durance is one of my favorite characters in the game. Having said that, I can definitely see why some people would dislike him. Especially people who don't particularly like confrontation and/or typically avoid it when possible.
Xoti on the other hand drives me insane. Here is a character that is insanely devout to a God that is traipsing across the Deadfire laying waste to basically everything, despite the fact that the Watcher, Eder, Aloth and Pallegina are all acutely aware that the gods are "jumped up Engwithins" that put themselves on a pedestal. I find it incredibly hard to believe that she wouldn't undergo some SERIOUS reflection given that knowledge. I also find it hard to believe that she wouldn't be shook to her core considering how devout she actually is. She's travelling with a group of people who have seen what the Gods are, what they've done as a result of their petty in-fighting and just how little they actually care about the people they supposedly "watch over". Her quest and/or mission is also a direct contradiction to what the Watcher is doing and all of the aforementioned. She wants to essentially hoard all of the "lost" souls so that Eothas can collect them at a later date in Hel, when the Watcher himself was tasked with sending them back to the in-between to return to the wheel for Berath. At no point is the watcher able to tell her "I won't stand for this" or "I don't agree with what you're doing" or "Berath tasked me with leading these souls to Adra" (Or anything in between), she interjects before anything can even really be said whenever something to do with souls comes up, and she acts as if her job is more important - despite the fact that the Watcher was literally brought back from the dead by a God to do their job. Both the Watcher (At least in my case) and Eder' consistently try to drill it in her head that she's basically a naïve sheep being used to further the circle-jerk that is the gods "non-plan" and the only response she gives is how she's right and it's her sacred duty. It's honestly infuriating at times, lol.