Watching the video gives me flashbacks of trying to teach someone to drive. Actually I'd probably prefer that than trying to babysit this headache in traffic. At least then I'd get paid for the hassle.
That's probably part of the calculus, but mainly it's to deliver at least something on an over-promised feature.
I also wonder how good the training examples are, if they're just using average drivers without any quality control. Like when I'm teaching someone to drive, I'm following traffic laws to the tee. But when I'm doing my day to day driving, it's mostly about optimizing time. There's probably a reason why Waymo hired and trained drivers to teach their algo in a standardized way.