Why did car lights originally stay on after the car was turned off?

Most newer models of cars now have a safety design that allows the headlights to stay on for a few minutes before shutting themselves off to allow the occupants to safely get to a door or gate. Also, on many newer model vehicles, if the lights are turned off before the ignition, the lights will stay off. If the lights are turned off after the ignition, the lights stay on to illuminate your way. If the light switch is off and the lights stay on longer than a few minutes, then something is wrong.