I'm opposed to my (fairly minor) copyrighted works being used in GenAI datasets as well. I just have no practical way to stop it, and there aren't clear enough damages to sue. That doesn't make it legal.
OpenAI also plays some ugly games with regards to the difference between training and search. Search requests come from the `ChatGPT-User` user-agent, and I'd like to allow those; training and scraping requests come from `GPTBot`, and I have no interest in those. But as per their own documentation, putting one in robots.txt disables the other.