I use it daily and I would be the first person to agree that it isn't 100% perfect, but not in the way you are assuming. The flaws it has are that it errs on the side of being too cautious.
Being overly cautious on the road is as bad as being reckless. The frequent example about 4-way stops is a perfect one. If a car is behaving unpredictably and stopping when it's their turn to go then it is creating a dangerous situation for everyone at the intersection.
Of course, it's a spectrum. It's nowhere near dangerously over-cautious. I'd describe it as a very prudent new driver. It drives the way most people probably should, but that means there's a little hesitation in low-risk scenarios sometimes. All you need to do is tap the accelerator and it instantly gets the message. We're talking about something that's barely an inconvenience, but it isn't the "100% perfection" the people here seem to blindly demand.