Why Are There Evil Humanoids?

d12
1. Humans trend toward the pretty damn evil, just not quite evil enough, gods went back to drawing board
2. They came from the future: universe started off pure order and good, slowly but steadily skews towards evil chaos until its terrible, incomprehensible end, evil humanoids time-launched refugees thereof
3. Victims of subterranean radioactive stone, emanations destroy good at metaphysical level
4. Brought into being to act as anti-humans by unpopular deities whose creative input was not requested for original creation scheme, throwing monkey wrench into otherwise charming plan for universe
5. Pawns in depopulation program by wicked aliens: secretly abduct humans in shocking numbers, plant seed of evil in brains, triggers permanent transmutations into various humanoid types, released into the wild as free agents of mayhem
6. Evil humanoids actually ambulatory fungi doing their best imitation of humans (note: all fungi inherently evil), a ruse to be dropped the instant the stars are right
7. Forces of Natural Selection in campaign world strongly favor evil, its a wonder any living beings possess even a scrap of decency
8. First came Primal Chaos, the substance from which all order and good accidentally developed, there is no reason for anything and its silly of you to ask
9. Seed of evil humanoids deposited when comet collides w/campaign world: weird hyper-adaptable space beings chose human-like form as optimum for requisite conquest of planet
10. Personified wickedness released from the Plane of Petulant Vanity by mythic prince: crafted the First Mirror in the Earliest Days, smashed it when reflection failed to live up to hype opening floodgates
11. Hilarious prank of otherwise transcendent cosmic entities unable to shake primitive appreciation of physical comedy, humankind perpetually, pitilessly punked for cheap laughs
12.  Philosophers hoist white flag: quandary of evil humanoid origins declared "unfathomable"