It sounds like you're talking more about a specific art form, collage, than art generally. Regardless, I am in the camp that "art is what artists do".

I think that a lot of the rejection about generated art comes from the fear that it would become the dominant artistic form rather than just another kind of art.

I watched a YouTube video the other day that expressed a sentiment that I share and that may apply here as well. He was talking about Photoshop rather than generative art: (Paraphrasing despite the quote marks) "As an artist, I love photoshop for the power and flexibility it gives me. As an art appreciator, though, I would never hang photoshop art in my home because the aesthetic is not appealing to me."