I don't know about the etiquette but isn't it all about giving a bit of consideration towards other people's needs and not just focus on our own?

If anyone is sleeping or trying to sleep nearby, I prefer to sit in darkness to help them to continue sleeping. I do not consider my preference for light or view to be greater than other people's physiological need for sleep. I would be mortified if I disturbed someone's sleep through my wanting to enjoy a view. But that is just me doing what I feel is the right thing to do.