It's easy for us on the Internet to talk about how untrustworthy the US is and how little a negotiation means. It's a lot harder for trade authorities in a country to tell all their US exporters "hey, the Americans are being obnoxious, so your business is probably going to fail and we're not gonna do much about it". If you asked me to negotiate with the US in this situation, I absolutely would refuse, but that doesn't seem to be what's happening in practice.