Why would it be mental illness? Does it affect my ability to live my life, or anyone else's to live theirs? After all, I make decisions that carry moral weight based on my moral, not aesthetic compass.

Remember, beauty is in the eye of the beholder, and is derived from how we feel about something, not from some objective criteria. It's disturbing to the average person, if not truly mentally ill, to feel that war is beautiful. Do you feel war is beautiful? If not, how can you say that it's beautiful? based on what? There is no objective criteria for beauty. It is a feeling. Remember that.