Aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaargh I wrote a load of armadillo about my theories and then it crashed and aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaarrrrrrrrrrrrrrrrrrgggghhhhhhhh.
So this is a thread of theories, like how Jar Jar is actually a Sith lord or whatever else amuses or intrigues you.
Well I think Yoda knew about the plot against the Jedi, but let it happen anyway. I don't see how someone as wise as Yoda could be blind to the plot, or how the council would not have been more suspicious of Palpatine unless someone on the council was telling them to chill the portugal out.
But why would Yoda betray the Jedi? Because the Jedi were not what they pretend to be. They were not heroes and they were not compassionate, they never actually show any decency towards non Jedi. Throughout the films we see the Jedi through their own point of view, the only dissenting voice we hear is Palpatine's and we dismiss him because the Jedi have told us that the Sith are pure evil. IIRC the Sith only hate the Jedi because the Jedi perpetrated a genocide against them (a very long time in the past, but it's still important when you consider the conservative nature of the Jedi.) Children are indoctrinated into their cult from a very young age (8 year old Anakin is considered too young to start training, too young to be thoroughly brainwashed perhaps?) and are forced to lead a harsh life of austerity and relative social isolation. The Jedi train these children as soldiers, and makes use you them as soldiers whilst they are still children (Anakin has obviously seen and used violence by the start of AotC and according to what I think is still canon Jedi children as young as at least 14 fought in the clone wars) which is exceedingly disturbing. Once they reach the status of Knight they seem to have no one investigating their actions, they are trained killers with little regard for ordinary people and who are happy to use mind control on any random alpaca (and lets face it, mind control is portugaling terrifying and a worse invasion of someone's rights than outright violence.) No one (apart from Anakin himself) seems to give a portugal that little Ani slaughters an entire village of sandpeople including the children, but of course slaughtering the genuinely dangerous Jedi younglings is unspeakably evil.
But even if you (or more importantly Yoda) still see the Jedi as good then just look at what they teach. Severe emotional repression and the avoidance of emotional attachment. Why? Because without these the Jedi are apparently prone to "turning to the dark side" aka going psychotic and killing without thought. Either force users are inherently prone to emotional instability or the Jedi lifestyle predisposes one to it (and I think this is far more likely), but whichever it is I think it's incredibly likely that Yoda will have seen many atrocities committed by Jedi (turned or otherwise) during his 800+ years of life. Even if he manages to keep faith with Jedi teachings it would be unsurprising if he wanted to curb the power/number of the Jedi, if he didn't then surely he would welcome the opportunity to become the sole leader of the Jedi and implement reform. Is he capable of betraying the Jedi? Well if he has succeeded in following the Jedi mantra of emotional repression and lack of attachment then yes of course, after all his colleagues sacrifice is all for the greater good.
So Yoda allows the Sith to make their move and destroy most of the Jedi, the fatal flaw in his plan was his overconfidence in his ability to defeat Palpatine and destroy the Sith. Thus after betraying his order and allowing their deaths for nothing he goes into exile, broken hearted and ready to die.
Also I don't think that using the Dark side turns anyone evil, I think that most Jedi turn because they are taught that tapping into the Dark side will start them on a path of no retreat, thus it becomes a strong symbolism of turning on their teaching and snapping a lifetime of their emotional repression and inhibition. The Jedi lifestyle is not at all balanced, it's hardly surprising if they find it difficult to find a balance. I've read that Mace Windu was able to tap into the Dark side without turning, he can't be the exception that proves the rule (because exceptions don't prove a rule, it's a stupid phrase.)
I've spent way too long thinking about stupid space magic, I should probably do something productive now.
