If emotions can be trained or conditioned, then there is no subjective definition of art. I can argue that someone just do not have the right conditions to appreciate something as artistic.
From my own experience I believe that the above statement holds. I have been told that I have a different and conflicting web of beliefs, and I feel the same. My thoughts often right me and disgust me at the same time.
When I love some art, I feel it like an irrational impulse, almost straight from the brainstem. Asked about the rationale though, I would come up with very complicated explanations that I do not even believe myself.
If I happen to appreciate some immoral subjects, should I go on the defense and claim that the environment changed me for the worse, or should I be proud of my nature, as modern society superficially encourages?