That is their perogative. It's still antithetical to the whole concept of art, and if they sell AI generated images as art, then they are no longer artists, but just a middleman for generative images. Whether those images were trained on art or not.

AI art is also really prone to breaking when fed AI generated images, so it needs artists to work, but it's use in the industry devalues the artists labour by being able to flood the market with low value replacements for art, thereby pushing actual artists out of the market and it's own training pool. If the art industry cannot support professional artist because they are driven out of the industry by falling wages, then there will almost only be AI images left, accelerating the staleness of AI generated visuals.

Artists intent makes the artist, not the ability to make images. Otherwise art would have ceased to exist when cameras got sufficiently capable.