Sure, there are plenty of things to dislike about DMCA or any other modern copyright law, but in this context the discussion was specifically about using DMCA to take down an unauthorized republishing of a copyrighted book online, which is a pretty normal application of copyright law. So I don't really understand how "AI is bad because it's trained on stolen work" but also "it's bad to take legal action against people distributing your work".

Lehman (a lobbyist) did an end-run around congress to the WIPO, to use treaty law to force the passage of the DMCA.