There are lots of safety arguments for street lighting.

For one, as a city dweller, I would be absolutely terrified walking around at night, having to rely on a flashlight to see anything. Not just a "scared of the dark" thing, but good outdoor lighting discourages things like robberies and assaults. And sure, cars could just use their headlights, but still, visibility in populated areas would be very bad, and safety for pedestrians at night would be awful.