I agree with Soundwave. Movies are a medium for expression. They are supposed to do a number of things, though not necessarily all, including: Communicate emotion; inform; entertain. Of course, every viewer has their own opinion on what is entertaining or inofrming or whatever. Some would find not having a coherent or logical story to be a hindrance, but others may see value outside of that. The arguement would extend depending on what the purpose of the film maker is, and whether inerpretations are going beyond the makers intentions. But whatever the purpose, successful films have to relate to the audience on some level, whther it be by shock, nostalgia, or familiarity. Plausibility is important for some, but others see theme as a higher priority in the enjoyment of film. i mean, Eraserhead -> ???
But I just want to chime in about the Midichlorians. They don't explain the force, merely the connection between the Force and those that are force-sensitive. The Force itself remains no less mystical to me. If anyhting, it's explaining why some people are more attuned to the Force, adn others aren't. I will admit, though, that even explaining this removes the whole notion of relating to the character. One reason why Luke succeeds as a protagonist in A New Hope is because he is a humble farmboy, who, under a number of consequences ends up saving the galaxy. That could've been me. It's somthing kids love to watch and dream - "I'm nobdy now, but I could be somebody!". Anakin in the PT fails, because he is the chosen one. He is Jesus from the very beginning, being immaculately conceived and pumped full of midichlorians. I'm normally against the whole fanboy notion of explaining things in sci-fi films on a technical level (a la Star Trek) - these kinds of things are against the point of real science fiction.
I liken my viewpoint of science fiction to Asimov and Philip K. Dick's. They viewed science fiction as separate from 'sci-fi', which was the modern action-adventure films, with spaceships, aliens and lasers and stuff. They saw a 'true' science fiction as something that was rooted much more in reality. In a science fiction world, typically, the world is the same, bar one major aspect - and this aspect is used as a tool to communicate an idea or theme inherent to humanity. Often it is something small that is exaggerated. It can make you consider your own world. Like in Gattaca, it was about the trial and triumph of an individual who had no reason to succeed - the difference in that world was the prejudice of genetically predisposed "invalids". In Bladerunner, it's the concept of the value of life - what if it's artifical life? And in the Matrix, it's the concept of reality that is altered - and this is used to make the audience question their own ide of perception, even though it has all the wire fu and fantastic action pieces.
Matrix is as science-fiction as you get (well atleast the first one). Star Wars is more of a fantasy.