Problem is that disgust can also be rationalized using that argument for bigotry and discrimination. Also, what does torturing a wrongdoer do for us? Hitler washes up on an island and you do the most heinous possible things you can imagine. What kind of person are you after that?
There is the argument that making bad people suffer ruins our morality. If we're better than them, then we don't want people to inflict suffering.
I heard/read this before, and I'm convinced by it: torturing someone does something not only to the victim, but to the torturer as well.
The act of torturing someone does something bad to you, regardless of whatever other effect. The kind of person who would torture someone in cold blood is not someone I want next to me.
There is the argument that making bad people suffer ruins our morality. If we're better than them, then we don't want people to inflict suffering.