i think the difference btwn roman and the siblings, regarding his view of the company and logan, is that he doesn't really abide by a system of "deserving" or "morality" so, he never has to express his disappointment in such a way. like, roman doesn't think he "deserves" anything for being "good," wherein "good" is transcendent/universal. for roman, "good" is merely determined by logan's subjectivity and roman doesn't even have to really agree with it or even totally adhere to it, just appear to logan as though he does. ultimately, roman feels as though logan's power over him is the most real and it is something they both agree on to some extent-- a child is beneath the father, the feminine is inferior to the masculine, etc.
roman's question is said out of frustration, disappointment and fear but, i wouldn't say anger and certainly not indignation. it read as another way of asking logan if this is "real." it shows him trying to come to terms with the fact that logan may never love him the way he wants him to. this was hinted at before when roman gestured at leaving when logan said he needed someone "ruthless." roman knows he's not that and logan saying this might mean that he doesn't want him as he is, that he just needs someone to fill a spot. roman stays when logan flatters roman's intelligence, something logan has often dismissed or outright denied but that roman seems to believe in. logan does fuck up a bit by saying that the "needs" roman rather than "wants" him which of course, still communicates the idea that roman's just a body filling a spot. roman accepts this regardless because it's this or his fickle distrustful siblings who want to kill dad. the hope, for roman, is that he might not have to act as a "killer" again, to do things he feels uncomfortable with. the disappointment comes when logan tasks him with this final disciplinary measure to fire (kill) gerri, in response to his decision to go to connor's wedding over sweden. when logan asked roman one last time about sweden, he even said that matsson likes him because he "keeps it light," the closest logan could ever get to admitting roman's main use is being a honeypot trap. so, when roman asks logan if he's "being a cunt," he sees logan's "being a cunt" as hurtful but ultimately, not "wrong." roman simply isn't "the one" and that's okay even if it hurts, that's logan's decision and what can roman really do about that? like, it's not even defying logan's will because at that point, roman interprets logan's will as one that will reject him anyway.