It’s imperative for shades up in the exit row for take-off & landing; or ‘in the unlikely event of an accident’ = safety 101.
Otherwise, READ THE ROOM! Opening the shade onto a dark cabin while others are resting is egocentric. Some flyers have been up since the early hours are changing time zones and have missed sleep. BE KIND and look around you before jacking up that window shade on a darkened resting cabin. You can also use your words, and confer with your seat mates.