I think strong dialogue could be made to work in a roguelike though.
One idea I've thought of is to make it so most business the player has with NPCs can be resolved very quickly, but to have the option of asking more questions to get more information. That way, on your first playthrough you can ask everything and learn what's going on, but subsequent characters can quickly accept their quest (or whatever) and move on.
Oh yeah, and I forgot to mention this before, but Caves of Qud has a pretty good amount of dialogue with the NPCs you can talk to. There aren't many friendly NPCs so far, but the game isn't finished yet, so maybe we'll see more.