It's amazing how many people are willing to help train the systems by sitting alert behind the wheel and taking over when things go wrong. Most folk want to do other stuff and not be a baby sitter. I get it. There is nothing relaxing about city traffic and watching over a "student driver" makes it to my top 10 worst jobs list.
Anyway, for them to be useful in the future someone has to train the systems now and there are plenty of drivers paying for the right to do so.