Many people have said part of the reason TES games've had such shallow NPCs is due to the sheer number of them. What if they only did ~50, and allowed the rest of the characters to fade into the "ambience" essentially. Less dialogue for most, more for a select number. Dunbar's is actually 150 but for a game I think a smaller number is reasonable, but it's a rough number and you get the idea.
Obviously real human relationships are a whole different thing, but just drawing from the theme here, would you prefer a minority of the characters to be much more in depth for a sacrifice of some or most dialogue for the majority? I think I would. I don't really need to be able to talk to every guard about five different subjects, I don't need as many small quests and short dialogues with random townspeople.
How many memorable characters can you think of right now from Skyrim? My list is pretty small - definitely smaller than 50 let alone 150 - and I'm guessing so are yours.
