Why does the starship Enterprise have running lights? I know the answer is "Because that way other ships can see it. It's dark out there." That makes sense on airplanes, but are spaceships really navigating by looking out the window?
They have all those fancy sensors, scanners, holograms, and starmaps. They always go "I'm picking up a Klingon warship on our sensors." I've never seen Data pointing out the window and going, "Does that look like a spaceship to you?" I've never seen them come out of warp and suddenly Captain Picard yells, "Look out, lights! Hard right!"
Why don't they just put turn signals on the Enterprise while they're at it? And when the ship backs up, make it go "beep, beep, beep?" Seems like a waste of power to me. If you can't tell a spaceship is heading towards you at a thousand miles an hour, little lights on its nose aren't gonna help.