Car Laundry

I don't understand why people have those bars in the back seats of their cars that they hang up all their clothes on. I mean, I understand the purpose of the bar, but who are these people that have them in their cars? Is it a traveling salesperson? Do those even exist anymore? One car contained an elderly couple. Do they just flip through the rack, grab a couple hangers, and carry them straight up to their hotel room? Does it eliminate the need for luggage? Not that it's any worse than my complex travel system of duffels, backpacks, loose bedding, and box of shoes and liquor.