I always try to help as kindly as I can when someone asks for context about a novel or TV show that is set in another time or culture, but sometimes I also just want to scream "Context clues!", especially when they get angry at a character, because even things written in a different time or place for that time or place will usually have enough in it for you to figure it out.
For example, people will often say, "Why doesn't Edward just break his engagement to Lucy! He's so weak!" about Sense & Sensibility and then be angry at him about it. Yes, there are historical conventions that explain the reasoning which might not be understood, but it's also right in the novel. Multiple alignment good characters, including Elinor herself, praise Edward for not abandoning Lucy and for keeping his word. Even if one doesn't fully grasp the reason, it's clear that he is doing The Right ThingTM.
It seems like the way some people approach anything is to apply only their own values and norms to it. When I pick up a book written 250 years ago or watch a TV show that wasn't made in my country, I'm starting with the assumption that morals and norms may be a bit different than my own. If a character does something I find odd, I pay attention to other character's reactions to see if it's normal or not. If everyone makes a big deal out of something I don't get, I register it in my brain as A Thing that I should probably look up later. If a value seems really important, I think to myself, "They probably put this moral rule above others" (we share most moral rules across cultures, we just order them differently). This doesn't seem like rocket science to me. Do people not do this?
