"I know the drill on why the shade theoretically should be open in case of an emergency, etc, need to be able to see if there are any hazards before popping open the exit door, but I would simply open the shade if that was the scenario."

Really? So you've been in that situation before? You know 100% how you would react and the airline and the 100+ lives on board could count on your experience in this matter? The chances of you seeing a danger right outside of the door are a lot better if they are guaranteed that the window shade is open. The way to best ensure that is to remove the human element and make sure it's open.

In terms of your shade wars, did you step up and take responsibility for yourself and buy a set of a $5 eye blinds before the flight or are you debating with the FA without taking basic steps to ensure your sleep? The FA probably thought of that argument but was too nice to bring it up.