All due respect: I’ve never understood this argument. I understand Taoist traditions, but I can’t comprehend a “good dark side user”. Love and passion aren’t equivalent to darkness, they just lead you to it if you aren’t careful.
Dare I say it, I don’t think the Jedi did anything wrong during the Clone Wars. A genius outsmarted them. Had Palpatine not been involved Anakin would have either peacefully left their order or broken off with Padme and firmly joined their cause. I just can’t see the Jedi losing the PT because they were “too good”.
And yet there is that bit that is in several of the films where the Jedi admit they are having problems with the force. How would that be the case if they were just outsmarted. There is an imbalance. I see the imbalance (and I did before the ST) as the good force users ignoring the dark side of the force. They are taught to ignore it because it is too tempting. They are never taught how to wrestle with it and stay on the light side and maintain balance. That is why Anakin fell so easily. He was never taught how to fight the temptation of the dark side. So in the PT and OT you have the force splintered into the far light and the far dark. Jedi are supposed to be closer to the center. They should know how to tap into the dark side as needed, but not let it tempt them or consume them. The Jedi need to be in balance themselves. They have banned attachments because it could lead to the dark side rather than teach the young Jedi how to be attached and not be tempted by the dark side.
If the old EU lore holds true, the Sith started out as fallen Jedi. So the order split. And to balance the force the order needs to be whole again. Since people are not easily changed, the easiest way to do that is to wipe everything out and start over. Well, Palpatine wiped out the Jedi and the Sith tradition of only two, a master and an apprentice, left the Sith side vulnerable to defeat. We see Luke learn that final balance in ROTJ as he taps into the dark side to defeat Vader and the lets it go. Vader kills Palpatine and himself in the process leaving only Luke… until someone resurrects Palpatine (everyone confirmed that he was indeed dead at the end of ROTJ). Luke is balanced, but late Republic Jedi taught. As issues arise, the balance is not maintained. The ST we got is about perfecting that balance. So Rey is NOT Jedi trained in the Old Republic traditions, but has the original Jedi text… from the age when they were balanced. Luke noted she was not afraid of the dark side. To her it is all just the force. Revelation of her origins tests that balance, but she regains it.
It isn’t a matter of which side of the force you use, it is all in how you use it and why. The user must be balanced. The user must maintain control. Anakin was consumed by the dark side. Palpatine isn’t just consumed, he is the embodiment of the dark side. He is chaos. The Late Republic Jedi have made their order all about keeping order and following rules and avoiding the dark side at any cost. They placed good an evil onto the natural order of things when the good and evil lies in how the force is used, not the force itself. So the destruction of Palaptine does bring about the balance to the force because he is chaos and evil - the embodiment of everything bad. The first time Luke has just found that balance and all is good for a time. The second time, Rey is that balance and has destroyed even the Sith loyalists leaving no one to bring it back. The Jedi order has been reset to where it was 1000 generations before.