So, do you acknowledge that generating an image has a very low energy footprint?
To the other point: The claim is just begging the question, because learning is literally not "stealing". You could be calling it "plagiarizing" if the generated images were close reproductions of some original images, but this isn't even the case. The actual complaint against AI art a few years ago was that some artists's styles was imitated in some images, but this isn't even the case in this game. Or can you point to some artist who's style is clearly imitated here?
And most importantly: It's neither illegal nor immoral to vaguely imitate some artist's art style, but in this case this isn't even some existing artist's art style! So what exactly(!) are you even complaining about?