On a further note, what other playable races do you see as too goody-two-shoes? Are there any that are generally viewed as better than others but have canonical proof of not being perfect?
Draenei. I hear them being described incomparably virtuous, angelic and godlike, yada yada. But consider this - in their inter-planetary flight from the Burning Legion through the cosmos, they knew
the Burning Legion was following them, and they knew
the Burning Legion would destroy or corrupt each planet and each native race where the Draenei tried to hide. Despite this knowledge they went from planet to planet, over and over and warned no one at any of the places they fled to!
Think about the orcs prior to their deceitful corruption by Sargeras. If they had had a heads up would they have been on their guard? If the Draenei had been candid and upfront about what pursued them, they would have had allies probably, and certainly the native races would have been more on guard.
The "noble" Draenei could
have spread warning through the cosmos. They could
have informed and advised the ignorant and innocent worlds. They could
have galvanized a prepared resistance to the Burning Legion. They did none of these things.
They sat on this secret, took care of themselves, and bugged out every time the Burning Legion found them.
And Naaru. "Beings of Light." What have you seen them accomplish? Get their butts kicked by the Burning Legion, and one old sick vampiric one in Nagrand draws orc souls to it where they are consumed. You trust these alien crystal soul-suckers? Because one of them hands out obsolete bling in Shattrath? I've got beach front property in Shadowmoon to sell you if you do...