I don't think the people most worried about AI as an existential threat are very concerned about assigning blame to the AI. They are just concerned about the da

I don't think the people most worried about AI as an existential threat are very concerned about assigning blame to the AI. They are just concerned about the damage, full-stop. They are worried about AI companies making continuing progress in capabilities research without ensuring adequate safeguards exist alongside. It would be criminally irresponsible to build a nuclear reactor without very carefully considered safeguards, automatic shutdowns, failsafe fire extinguishers, and numerous other redundancies, independently verified by licensed engineers. Simply putting that nuclear plant in the hands of well-meaning operators is not enough. I haven't seen any AI companies acting with that standard of care. They seem to instead be caught up in a breakneck race to release products, attract investment, and maintain dominance, regardless of what their PR departments say. And so far the regulators have mostly been happy to leave it to them to figure out what safeguards are sufficient. That said, it certainly could be the case that companies like OpenAI are pretending to worry about this issue in order to gain regulatory capture, or as you say, to somehow absolve themselves from responsibility for the behavior of the systems they create. (As if that were possible!). It certainly seems likely that they would co-opt the legitimate concerns of third parties for their own benefit. And perhaps rocketry companies also exaggerate the existential risk of asteroids. But while we can question the motives of certain actors, the existential threat may exist all the same.