They were fine given the limitations of the Neverwinter campaign setting and the challenge of making it interesting. When your entire setting is about being a beacon of civilization and egalitarianism in the middle of harsh Darwinistic environment, you have to draw upon all the elements of culture that exist in that civilization and work out how they would respond to the challenges.
Every character in your party is the sort that would exist in Neverwinter. Their motivations are the sort people in Neverwinter would have, based on the conflicts that the people of Neverwinter generally face.
Man, where do you get your dope? It must be good stuff, I want some.
I don't smoke, just drink. I get my bourbon from the liquor store like everyone else.
Anyway, it's all rather transparent. The companions are colorless on their own terms, but as described in an earlier post they are permutations of different aspects of the Neverwinter setting. All Obsidian companion Influence systems have some tie to the primary theme of the game they belong to. In Neverwinter Night 2's case, society.
Khelgar -- fantasy equivalent of a biker. He goes and taverns and gets into brawls while his clan and society struggle against monolithic threats. Protagonist shows him how to respect the order that both his clan and Neverwinter need to survive and administer true justice.
Elanee -- social outsider who doubts society and its institutions. Is eventually shown (and comes to respect) the power of civilization through the actions of the protagonist.
Neeshka -- belongs to the criminal underbelly of Neverwinter's lawful good society. Like most criminals, she is a social outcast who has a grudging fondness for the city despite its aversion to her. Protaginist provides her with acceptance.
Sand -- lived in a despotic society where the law was administered unfairly and arbitarily. Didn't like it and ran away. Order is everything to him in both the application of magic and the organization of society, as shown in how he moonlights as a lawyer. His betrayal of a chaotic protagonist reflects that. He respects a protagonist who respects law as the force that maintains a civilization, ahead of what's good or what's bad.
Qara -- spoiled highborn girl. Like most teenangers, just wants to have her version of a good time and doesn't have respect for society or the forces that protect it. Her betrayal of a lawful protagonist reflects that. She respects a protagonist who is in it for his own kicks, ahead of what's good or what's bad.
Casavir -- Lawful Good Paladin who justifies his renegade actions based on the premise that the people in and outside Neverwinter, not Nasher, embody the force of law he adheres to.
Bishop -- inversion of the protagonist. The protagonist has a group of companions while Bishop is the consummate loner. Both come villages and went to the city to rise up in the ranks, but Bishop's hostile relationship with his village results in them disbelieving him when he tries to warn them about how Luskan is going to destroy them, so he destroys both the village and his own men in an attempt to break all bonds and all obligations. Wants the protagonist to be like him.
Ammon Jerro -- will sacrifice his soul, his family, morality, and the order of the Planes to protect his civilization. He is the ultimate personification of the maxim, "My country, right or wrong -- but my country." He respects that the protagonist is able to protect Neverwinter without depending on infernal pacts or deals, as in, the protagonist has the strength that Ammon lacked.
The Influence system in Neverwinter Night 2's is governed around the premise of trying to keep an entire society of wayward and disaffected individuals from breaking civilization apart. The inter-party dialogues and companion quests reflect the same tensions that are always tearing Neverwinter apart in the PnP and the game.
Amen, only games which made Commissar suffer more were DA2, Avadon and Oblibion; what a waste of time. Even Obsidian agrees given that you don't need NWN2 OC character to play MotB.
No, it's sort of like the Dollars trilogy. Only the Good, the Bad, and the Ugly gets serious attention for being a great movie, and its works by itself, but all the films resonate with each other.
That's not limited just to Mask of the Betrayer though. It resontes both with the Forgotten Realms metaseries that started with Baldur's Gate and also with all Obsidian games.
Planescape: Torment -- Regret, and whether to take responsibility for your actions (good) or transcend them (evil option).
Knights of the Old Republic II -- Betrayal, and what exactly treachery is.
Mask of the Betrayer -- Justice, and whether it is a force of law or balance.
Neverwinter Nights 2 OC -- Civilization, and the forces that defend and destroy it.