The one caused by Uber required three different safety systems to fail (the AI system, the safety driver, and the base car's radar), and it looked bad for them because the radar had been explicitly disabled and the driver wasn't paying attention or being tracked.

I think the real issue was that Uber's self driving was not a good business for them and was just to impress investors, so they wanted to get rid of it anyway.

(Also, the real problem is that American roads are designed for speed, which means they're designed to kill people.)