That is based on the fallacy that derivative creativity is somehow lesser than so-called “original” creativity.
The vast majority of AI art I've seen on sites like Pixiv has been 'generic' to the level of the 'artist' being completely indistinguishable from any other AI-using 'artist'. There has been very little of the sort where the AI seemed to truly just be a tool and there was enough uniqueness to the result that it was easy to guess who the creator was. The former is definitely less creative than the latter.