I obviously see the rants of my own echo chamber, but the complaints about GenAI are mostly about copyright (as you said) but they also make it a moral stand. GameDev using GenAI are accused of being "lazy", of having no vision, etc... unquantifiable.
Your remark about aesthetic would map 1:1 to poor code quality. (LLM code quality can be pretty bad, depends on prompt like always).
"Stealing" is a word aften use to criticize genAI.