That's the flip-side of Protagonist-Centered Morality. There is a very real and demonstrable phenomenon where an audience is more sympathetic to the audience P.O.V character than they might otherwise be to the same actions or circumstances of other characters. One person's terrorist is another's freedom fighter. One persons cautious compromises are another persons obvious terrible mistakes; and everybody judges each other with the full force of hindsight.
Nicki's entire existence is colored through the lens of Guy, and specifically his unreciprocated desire for her as more than a friend. The audience never gets to see inside Nicki's head, we're never made aware of her wants, needs, desires, or her thought process. Everything the audience sees is seen through the eyes of Guy. All we know of Nicki and her dipshit boyfriend are what Guy thinks he knows. Now I don't think NeonGhosts is necessarily out to make Guy an unreliable narrator, but you have to accept that Guy isn't omniscient or infallible. He is human, meaning he is subject to misremembering his misperceptions. There could be (indeed there almost certainly would need to be) things about Nicki's ex-boyfriend that she found charming, appealing, or endearing, in ways that we'll simply never see from Guy's perspective.
Also, anyone getting on Nicki's case because she's not a perfectly rational actor needs to get the fuck out of town (this is not directed at lorddarkam, but more so the thread in general based on what I've seen before). Nobody is a perfectly rational actor. Nobody. Perfectly rational actors are the wet-dreams of Libertarian thought experiments, they do not exist in observable reality. Humans are piles of swarming emotions, and one of the things most all humans are extraordinarily skilled at is post-hoc rationalization of emotional decisions.
I've said it before, but it bears repeating. Friends In Need is the visual-novel equivalent of the of the quote "You Can Easily Judge the Character of a Man by How He Treats Those Who Can Do Nothing for Him". Sure, Nicki has made some dumb mistakes. Mistakes that Guy would have preferred she hadn't made. But made them she did. So when Nicki arrives on Guy's doorstep as an unrecognizable mess with nothing to her name but the wet clothes on her back, how Guy reacts speaks to the core of his character (and by extension, that of the audience, since this is a choose-your-own-adventure visual novel).
Indignation? Retribution? Extorsion? Antipathy? Concern? Empathy?
Nicki can do nothing. She is effectively powerless here, and they both know it. It is a power dynamic that continues to loom over their interactions from that point going forward. She knows in her bones that at any second, Guy could just pull a repeat performance of her ex-boyfriend, or the sugar-daddy photographer, or the porn studio loan shark. Now as the audience, that probably would never even cross most of our minds; the thought of subjecting Nicki to that abuse yet again. Protagonist-Centered Morality striking with a vengeance. But depending on the path taken through the game, Guy may have already come close. Even if he hadn't, it's smart writing and characterization on NeonGhosts' part that Nicki acts the way that she does.
Love her or hate her, Nicki is a character. Polarizing? Sure, but so are people. But how a person reacts to her says more about them than it does Nicki herself. But the one thing I think we can all agree on is this; Nicki isn't boring.
The only way to stop it was changing myself though and taking responsibility for my own role in it. Not by blaming the world I had become a victim and keep doing the same things.
