>>3200347>>3200356Sometimes the subject matter is the setting itself. To truly appreciate night photography you need to appreciate the dark and light of it all. It's the ambience, not necessarily what's contained within it but the overall atmosphere.
Your reasoning that the setting wouldn't be interesting in daylight doesn't hold true, because it looks completely different at night. The bright colours are brighter, and the darks are even darker. Shadows come out, lights come on, and light doesn't behave the same way in front of the camera.
Personally, I love environmental shots like that.