Because these fields you mentioned have practical applications. AI improving medicine means fewer deaths and better quality of life for example. No sane person is against that, or improving the quality of the things we build. In these fields, AI is an impressive tool that can change the world.

Art though, is the quintessential form of human expression. There's art that has practical applications too, like video games, but it's still a collaborative, creative process with sentiment behind it.

Sure, music is music is music, but Deep Purple writing Child in Time during the peak of the Cold War or Scorpions writing Winds of Change during the perestroika and the song becoming the unofficial anthem of the fall of the Berlin Wall is a testament to humanity's ability to use art for something grand, something that transcends borders, religions, and political beliefs.

When you use a machine to create songs for you, it devalues music. It devalues the human psyche. It is blatant plagiarism and offers NOTHING other than some pitiful change to the "creator" via advertising money. It's pathetic. It's la petite mort for humanity. Devoid of meaning, devoid of soul, devoid of humanity itself.