You forget, Ruin was not evil. He put it quite well actually. Morality doesn't even enter the equation with him and Preservation. Likewise, Cultivation and Dominion are not necessarily good or evil, they are simply doing what they do.
Devotion is a tough call. Does being forced to love count?
Honor is difficult as well. But then again, Szeth is honorable, and yet what he does is terrible. He has a choice in the matter, so is he good or bad?
Odium would be much like Honor and Devotion if not for one factor: Its holder is evil. Odium hates all, and is driven by it. He seeks to be the only thing left in the universe (Sounds like Raistlin almost...), and refuses any shard that might change his vision. Odium wants to be evil. Though the Shard itself may not be inherently evil, the current version of Odium is.