It's probably unnecessary to look for grandiose and irrefutable explanations as to why we choose to act on certain instincts and not others. Maybe it's a symptom of religion. Or just of choosing to believe that art can do far more or far less than it really can.
I like to think there's a reason why, when describing art, religious terms are the only ones that feel large enough. It really does feel like the holiest experience and the one worthwhile act, or at least the closest thing I've found. I'm ashamed of how often I wish to be wrong about that. I want so badly to know I'm not just adding to the noise.
I still believe art can heal, but maybe it only heals the artist.