- you have guests staying over
- have a small child who is afraid of the dark
- make it a habit to leave hazards on the floor in random places.
Studies also prove that exposure to bright lights in the middle of the night mess with your body's internal sleep cycles. Properly functioning "smart" nightlights will remedy this situation. The kicker is that using the nightlight will save you money over time vs. turning on the full bathroom light.
Incandescent lights are not efficient, they generate a lot of heat and the bulbs burn out. Get rid of your old school night lights and upgrade to a more functional model. Unplugging and plugging, or switching on and off "dumb" nightlights is ridiculous in the modern era.
Below is a model I recommend, just make sure the seat is down when you're done :-)