I feel the same way. I just can't connect with fiction that doens't contain some spark of decency in its narrative and on a bit of a tangent I feel the same way about fiction with a totally nihilistic bent(even though I have a bit of a 'what is the ultimate point' streak in my personality sometimes). It doesn't feel realistic to me, because humans are capable of both extremes and a world which excludes the positive totally, seems as unrealistic as a world where the negative is totally missing. I have a bit more of a tolerance for totally positive worlds, because they're comfort food, but there are some that still bug me.

'because she's looking at the dark side of whatever comes into her focus' Oh that's a useful second interpretation. Yes, maybe she just wanted to look closely at that negative side, on its own. I did worry I was being a bit over defensive, but Nadia's character just got under my skin as she was a terrible person and a huge part of what made her awful seemed to be her privacy issues. On her own she would have just been a horrible person, but the pattern that seemed to develop set what could be seen as excessive privacy at the heart of bad relationships.

I'd be interested, if you do ever read it, to see what you make of Weissz's request that he needs a room which his wife will never enter. In the novel it seems to have been a wedge between them, making part of him permenantly closed to her. I found myself becoming more sympathetic to his request as the novel went on.