The Democrat decided to reject the measure because it applies only to the biggest and most expensive AI models and doesn’t take into account whether they are deployed in high-risk situations, he said in his veto message.
Smaller models sometimes handle critical decision-making involving sensitive data, such as electrical grids and medical records, while bigger models at times handle low-risk activities such as customer service.
Good analysis of this from PauseAI:
I don't want to presume to paraphrase their analysis into one phrase, but if I were forced to, it would seem to be that there was a lot of pressure on Governor Newsom from powerful AI companies and interests, who also threatened to ruin the bill's sponsor Scott Wiener.
Still a pity that he couldn't resist the pressure.
It's kind of pathetic, but this is the reality of politics today. With their money, they really can either make or break a politician, and we voters are not smart enough to avoid being taken in by their negative advertising and dirt-digging.
It's clear that we need a much stronger movement on this. The other reason he was able to veto this bill is that the vast majority of people do not agree that AI poses a major / existential risk, and so they do not insist on the urgent action we need.