People read fanfic for as wide a variety of reasons as they read anything else. Some enjoy comfort fic - like the much maligned coffee shop AU - and some want to dive deep into tragedy. I myself like anything that actually lets characters slow down a bit and address their issues; so much media (particularly visual)…

And he always seems to make the source of stress external, rather than arising naturally out of personal conflicts.

Nick and Nora types are uncommon not because people don't want to see them, but because they are hard to write.