Writers can create crazy plots, but unless it rings true, the audience won't connect.
First of all, I'm going to point out that I'm not talking about any specific genres. For example, science fiction or fantasy may not ring true to most people because it's a step away from the world as they know it, but I'm not talking about that aspect. I'm referring to the substance of the story and the characters involved. Is what they're doing in a given situation make sense? Are they reacting appropriately when considering their experiences, history, ethnicity, health, beliefs, age, and the people in their world?
For example, I recently watched a television show where a couple hired a live-in nanny to look after their children. So, what didn't ring true? She was a total stranger with no (known of) experience and, as far as I can tell, no credentials. These characters are wealthy and live in a mansion, which adds an extra layer of wtf. What's wrong with this scenario? Does it ring true? Would most parents, let alone rich parents with resources, hire a total stranger to look after their children? My guess is no.
Our logical side is automatically skeptical in the same way as when we hear a lie. This same skepticism tends to move us away from the character because regardless of what disastrous thing this babysitter will potentially do, we're wondering why the hell the parents so casually hired a stranger in the first place; Are they unfit? Stupid? Are they too self-involved to think about their children's welfare? It doesn't make us root for the parents, but the children. So, unless this story is slanted to create compassion for the kids involved, it's not working. The viewer/reader must feel some connection with the character to be drawn in. So, unless you're also careless with your children, chances are you're not on their side.
Again, we have to consider many variables. Maybe if this family were poor, we'd have more compassion because they mightn't have as many options for childcare. Were the parents neglected as children, so didn't recognize that it was strange to hire a stranger to look after their children? Is it normal within their culture/family to be goosey loosey when looking for babysitters? Are they young, inexperienced, as parents? The point is that this situation normally wouldn't ring true. It just seems kind of stupid, actually, and makes me question if the writer just threw it together as a way to work a character into the storyline.
Can you think of books, television shows, or movies where things didn't quite 'ring true' for you? On the other side, can you think of a character you connected with and why?