Art generators can be used by people who would otherwise have to pay artists, so they're in competition with the people dissing them.
Code assistants are used by programmers wanting to be more productive. Things that claim to replace programmers entirely get dissed. (But it's more "that won't work" rather than "that's not allowed", because, well, it doesn't work. Yet at least.)
AI-generated content is probably cheap spam, even though it in theory could be made by someone knowledgeable using the AI as a tool.
Things generated by an AI are lower quality than things made by someone competent... but depending on what you're doing, that might not matter.