So, Everyone should know the story by now. Shaohao was the Last Emperor of Pandaria and the one who, ultimately, created the Sha. Long story short, he saw what the Highborne were trying to do at the Well of Eternity and despaired. In his long search for a way to avoid the impeding doom, Shaohao went to the Jade Serpent, who counseled him to purge himself of all evil within, to become a pure spirit. The Emperror didn't know how to do this, but his companion the Monkey King inadvertently provided him with a solution - Provide his doubts with a physical form and wrestle it down. Shaohao then did the same thing to his fear, despair, anger, hatred and violence. The Sha were then beaten and imprisoned beneath the earth.
And this was stupid.
You see, what Shaohao did was to actually empower the evil aspects of himself he was trying to defeat in the first place. By giving them shape and independent existence, he provided the Sha with more opportunities to harm Pandaria, not less. Now, instead of struggling with doubt, fear, despair within, the Pandaren have to do actually ignore these feelings, under penalty of awakening the Sha and destroying their homeland.
Before, each mortal being would struggle with his or her own shadow, and then, if victorious, come back better from the ordeal. Now they have to live in perpetual denial and vigilance. It was a futile effort, in the end - Fear, Violence, Hatred, all still exist, and now are harder to beat.
One of the guys in Paw'don village (The brewer, can't recall his name) tell us that their emperor told them not to live in fear... But that's what they do. It's not a constant presence, but it's there, in the background. Keep constant watch over yourself, or you'll release the Sha. Don't feel anger, Don't feel fear. Don't ever doubt yourself.
And that's, of course, is all without going on about some og the things he took from himself were not that bad.
See, Violence can be bad. But it's necessary, sometimes. You can't trade in diplomacy with Deathwing, or Arthas, or the Legion. You have to beat them back, full force. This leads us to the second point - Anger is also not necessarily a bad thing. Righteous anger can be a powerful tool for good. The Draenei are one of the most goody-goody races out there, and their main military force are called Vindicators. Vindictiveness. Revenge. Anger. Also, Varian's quote about rage in defense of family and land.
Then doubt... Look, doubt is good. Doubt makes us moral. Arthas didn't doubt about taking up Frostmourne. Illidan didn't doubt about allying himself with demons. Thaurissian didn't doubt about summoning Ragnaros. Hesitation is a good thing. Actually, since Doubt was the first thing Shaohao diverted himself of, he couldn't see the evil he was doing, even if he wanted to - He had effectively removed his ability to admit he was wrong.
Even fear can be a good thing. Fear helps us survive. Fear makes us cautious. Fear for our families and friends is what makes us care for them. Fear from becoming a monster, like Tyrande fears becoming Azshara Mk II, is also a good thing.
I'm sure Despair and Hatred also have their part, even tough it's hard to see. Like a wise Naaru said, without the Shadow, the Light cannot exist.
So, yeah. Nice job breaking it, Emperor. And now it comes to us the duty of not only beating back the Sha, but convincing the Pandaren to embrace the full emotional spectrum, to allow themselves to live and feel fully.
And no amount of finger-waging is going to keep us from that.