I can understand someone turning them on in flight (if they want to), we don't and I don't. They're also useful for refueling at a remote location. However, I absolutely hate having to be shot in the eye with them during taxi, and since most airlines around here seem to mandate them being on 24/7, they're quite distracting at night during taxi.
Once had a hard time making a 180 into a parking spot because the Lion Air 737 decided they needed to be on while parked.