It's the small touches that really make a world come alive. Graphics and art can only get us so far, but it can never go beyond the superficial.
I still remember back in EQ, we had to /hail the NPCs, /con the creatures. Nightfall brings out the real dangerous monsters and we really had to hold up a torch to see at night. Now in FFXIV, night is just bright as day, we don't really care what level monsters are anymore, it's perfectly safe to navigate most zones because there are defined paths and monsters can be kited by absolutely every single class. Darkness makes no discernible difference and quest markers all but play the game for us.
They really need to be a little more alert. There should be about 15m or so radius in which any combat action will cause aggro regardless of facing. It's things like this that make the world feel shallow.