Originally Posted by PTravel

Not a good example. A car horn is intended to be a safety device. A reclining seat is intended to be a comfort device. You blow your car horn when you need to warn other drivers or pedestrians. You recline your seat when you want to be comfortable.

...tray tables weren't originally, intended to be desks, notwithstanding the fact that they're certainly used that way now. They were intended to be a place to put your meal tray. ...It's the recliner's call, absent a compelling reason for not reclining, e.g. "you'll break my kneecaps," "i'm in a cast," etc.