(Sorry, I'm so sorry about this.)
Neither Yin nor Yang are absolute. Nothing is completely Yin or completely Yang. Each aspect contains the beginning point for the other aspect. For example: day becomes night and then night becomes day…Yin and Yang are interdependent upon each other so that the definition of one requires the definition for the other to be complete.
And...
The balance of Yin Yang can be skewed due to outside influences. Four possible imbalances exist:
Deficiency Yang
Deficiency Yin
Excess Yang
Excess Yin
These imbalances can be paired: so an excess of Yin can also simulate a Yang deficiency and vice versa.
The force moves through every atom in the entire universe, so the force is possibly almost as big as the universe, if you could measure it stem to stern.
Really how can a handful of ###holes, with super powers that at their worst or best are about as heady as a small planet bound thunderstorm, uproot the universe?
The universe can't care about the (relative) drop of force being used or misused by "people" when the force is probably also what keeps the galaxies in orbit of each other.
Sure the term balance in Taoism (from 3 minutes of reading) is not about 50/50, but the reaching of a stable equilibrium after a period of flux, but even that's not discounting my impression of canon. Lucas' impressions arn't canon either. If George's got some bright ideas he should have put in the movie but forgot to, then logically after even the Special Editions, if he's still not added those bright ideas to his movies, then if what's in his head is still not in the movie, it's still not canon.
(Wow, in the distance behind me, is that the deep end or a cliff face?)
Taoistically, how was the Force in Flux during the Old Republic? The good guys were at their strongest and there was no end in sight. Hells, even in the end the Jedi were not defeated by a direct attack from the Sith, or an overwhelmingness of Sithness but by the politics and treachery of ordinary mundane people laying a massive clone army shaped booby trap. The Emperor didn't win because he had magic powers or he listened to a guiding magic voice in his head telling him how defeat one person with a laser sword standing 12 feet in front him who is also listening to a magic voice telling that guy how to defeat the Emperor... Force Neutrality? The force is bipolar? But even when Sith fight Sith or Jedi fight Jedi, there's still a magic voice telling the Jedi how to kill Jedi and the Sith how to kill Sith. The force is playing itself, and doesn't care which side wins, or the side being punked into listening to the magic voice that tricks them into losing will stop listening to the magic voice in their heads.... (Wow. It totally sounds like I'm talking about Schizophrenia.) Sorry. The Emperor won the trilogy not because he is a Sith, but because he is a cunning bastard.
Maybe the imbalance problem wasn't that Jedi numbers were massive compared to Sith numbers but that the Jedi Numbers continued to grow, and grow and grow and grow while Sith numbers did not, or did not at all proportionately.
Flux vs. Balance.
...
My read on this has always been that Yoda and the Council thought that balance was a good thing (like you all say it is), that balance would mean Jedi enlightenment (like some of you say), even though it had been thousands of years since the Sith Wars, so the presence or absence of Sith shouldn't have been anywhere near the fronts of the councils fears or drives in the slightest. Is anyone currently currently afraid of being pillaged by the Visigoths or Normans?
No? Maybe?
Considering how Anikan eventually fulfilled prophecy, they "obviously" misunderstood the prophecy while it was still just some flowery verse in a book, because if what Anikan did had any relationship to what they thought he'd do, then he fulfilled prophecy though decimating the Jedi, so therefore the prophecy had been that he would exterminate the Jedi. Personally I just thought that at some point in the third movie after seeing Vader mow through all those younglings, that someone was going to say "OOOOH! BAAA-LAAANCE! Yup, balance, I totally get it now. He's bringing balance to the Force by decapitating school children. I am such a moron, moron, moron, It's so fricking obvious now. Balance!".
If the Council thought that Anikan was prophecy boy, and maybe he wasn't, some say Luke was prophecy boy, and Anikan had nothing to do with the balance prophecy, so little orphan Annie is just some guy who killed a bunch of kids to get the secret of bringing his dead secret wife back to life who was still alive, and had nothing to do with bringing about a new golden age, then exactly what sort of Stygian dystopic hellword did the Council assume that they were living in then in the last days of the Old Republic that they needed to be saved from the Glory and might and beauty of the new republic pre-Palpatine by a chosen one and his new Golden Age?
(After seeing the new movie, explain to me how Luke brought balance to the Force if his first class of students spun out, and generated a school yard massacre (Wait? Was that intentional social commentary or an accident?) and then Young Skywalker goes to hide on a hill for 10 years. So it's Rey who bring's balance as the Force awakens? #### it, I'm starting to think that the best balance is achieved in a galaxy without force users, which is really what happened when the Jedi were destroyed, since the Sith presence was over-all completely inconsequential.)
I'm believing that parallel universes exist in Star wars, and that midichlorians live their lives backwards through time, which is how force users see Futures that do happen and also futures that do not happen. So the Emperor sitting in some high castle scanning the futures with his Sith Brain and then leaning into one future or the other by pivoting his Empire's resources might be slightly harmful to the the natural grooves the multiverse thought it was making for itself, like when a river gets pissed off after some bugger (or a beaver) builds a dam.
The Jedi were religious fanatics who have proof that their religion should be fearfully obeyed. Think of all the Christians who only behave well to avoid being smote by a nonexistant god? If the Jedi disobey prophecy or treat prophecy with bad faith, civilizations fall and the conditions/definitions of entire speices alter. If they will do bad things to ensure the greater good, how are they any different than the Emperor (if that even is his modus operandi)?
If the Jedi thought that pulling the Old Republic down was the best course towards bringing balance to the force was a good idea, they would have steamed full power ahead because the Forces relationship with everyone in the universe is far more important than one cumbersome government's right to exist.
Church vs. State.
PS
Once Palpatine was the Chancellor, the best course of action WAS to pull down the New Republic... But the Jedi did not know that because Palpatine was clouding the future and stopping the council from seeing his end game and how to route the Dark Lord.
1. They must have meant that Anikan was going to bring a New Balance to the Force.
2. New Balance is a popular brand of sneakers.