There's nothing quite as beautiful as looking out the window on an eastbound TATL crossing early in the morning before the sun has risen, and seeing the changing colors as the day comes on. And on a transcontinental, I never get tired of checking out the scenery below from the missile silos in Montana to the Rockies and the Sierra Nevadas.
If someone wants darkness, they can wear an eye mask. And keeping the shade, if manual, halfway down shouldn't affect those looking at video screens too much.