I've always tended to think this comes under common sense and awareness of the situation, which makes me wonder how it's such a subject for discussion...

In my view, if it's an obvious day flight (like LHR>LAX outbound), then having the blind up is broadly reasonable, it's reasonable for people wanting to sleep on that flight to use an eye shade as it's going to be a minority pursuit but, over the mid Atlantic with nothing to see, if somebody asked politely if I'd mind closing it for a while, I would do so because why not?

Conversely, on the return LAX>LHR, sleeping for 7-8 hours is the majority pursuit and I'd not dream of insisting on keeping the blind open for half the flight because I couldn't sleep or needed to get some work done and fancied it, I'd be embarrassed by the rudeness of it.