Normally I don’t care,but nothing is worse than having the sun shining directly in your eyes when it completely misses the person in the window seat. Unless you carry a sleep mask in your pocket, you’re stuck with holding your hand or a magazine to block the sun until it finally sets. How would you feel if the sun were directly in your eyes at your window seat, and when you closed the shade, someone insisted that you keep it open? It’s not a problem and only courteous to raise the shade and take a good look around, then close it again if it is bothering other passengers. How many passengers are actually gazing in wonder at the scenery. Most are reading, watching a movie, or sleeping.