The one thing that always bugged me about the Star Wars prequels (aside from the whole "I don't care about these characters" part) is that it made The Force biological rather than mystical.
In the original movie, Obi-wan explains to Luke that The Force is an energy field that flows through all living things, it connects us and binds us. I always thought that was pretty cool and it isn't too far removed from my idea of a "higher power" - greater than us, something we can feel, yet wholly unlike the traditional idea of some bearded dude on a cloud.
Well, in Episode 1, it's explained that The Force is a product of a microscopic, measurable entity in our bodies called midi-chlorians. The more midi-chlorians you have, the more Force you can wield.
Well, that sucks. Sorry, George Lucas, I really love the universe you created, it's been a huge part of my life and my thoughts on good, evil, hope, bravery, you name it... but you fucking blew it with this. In the original trilogy, The Force was something you could learn about, learn to use, tap into for strength. In the prequels, it was something you were either born with or you weren't. If you had lots of midi-chlorians, you were awesome - if you didn't, well, sucks for you.
That's bullshit and it goes against everything the original trilogy stood for - namely, that you could be a nobody who could rise up and become somebody. You could even be an orphaned farm boy on a shithole of a planet and end up literally saving the galaxy. That was inspiring. The whole "you're either born with greatness or you aren't" angle is anything but inspiring.
I hated, hated, HATED the whole idea. Thanks for ruining the whole point of the movies for me, dickwad. Oh, and HAN SHOT FIRST.
Chronologically, the prequels and that story line came BEFORE the original movies. That means that Obi-wan, who was 100% on board with the whole midi-chlorian concept when Anakin was a boy has apparently ditched the entire concept of that by the time he's an old man exiled in the desert. In other words, midi-chlorians could've been something that everyone assumed created The Force back in the timeline of Episode 1, but by the time decades have passed and we get to Episode 4, Obi-wan (and others) have learned better - that perhaps midi-chlorians can help a person tap into The Force more easily (and thus legitimizing the idea of "The Force is strong with this one" or "The Force is strong in my family"), but a person with a low midi-chlorian count can still feel and use The Force, though it would take more training and greater concentration.
This would also explain Obi-wan's description of The Force as an "energy field" rather than a microscopic thing in your body. It would also support the idea that it "flows through all living things" - which would be silly for him to say if it were just something in the blood stream. It would also support Han's belief that it's just a "hokey religion." You don't describe a body organism as a "religion."
So perhaps the prequels were simply describing an outdated understanding of The Force and how it works, which had been discarded as more was learned about it over time. If that's the case, then it would follow that there would be no mention of midi-chlorians in Episode 7. I haven't seen it yet, but if JJ Abrams is to be believed in interviews he's done, the topic won't come up.
So a whole new generation of fans can again say, "May The Force be with you" and not ask for a blood test first. A new hope, indeed.