I'm in the "does it hit an emotional truth" camp. My reasoning is that we have math, science, and logic to tell us all the other stuff. But (JMHO) we look to art to reach truths that those disciplines can't tell us. So if Joss Whedon sacrifices plot to get to the emotional core of, say, the B/A relationship, that's fine by me. In fact, I love it. Sure I can see the plot hole in the "gypsy curse", but I don't much care because the story brought me to the emotional conclusion.