There is a thing i'm going to call frequency dependent morality. Something may become good or bad depending on how frequently it's done or how widespread it is.

Automation is fine as long as it isn't too widespread. When one human activity gets automated, there are still many others to choose from. Humans can still be useful and have something to aim for in life.

When something like machine learning/AI is developed, and it starts eating up all human activity, automation becomes bad due to how widespread it is. When opportunities for humans start dying out completely, which is 100% the end destination of AI, there is an obvious problem there.

I think the fact that AI art might be the line that many feel can't be crossed is because it means something to them personally. Watching industry try to replace truck drivers wih automation should have pissed us off, but most of us aren't truck drivers and we didn't care.