Not unbelievable that their robot cars every four to five minutes had to contact a human for assistance. Not unbelievable because that's how a lot of YCombinator company's got to where they are ... fake it before you make it ethos (Reddit filled it's pages with fake content). Yet all those companies did not deal with machines that can harm people and or worse.
Why are people surprised that they didn't go from a 1:1 ratio of drivers to cars (namely a safety driver in each car) to 0:1 (i.e., full autonomy without supervision)? That would have been highly irresponsible. Any step function that can be turned into a gradient should be turned into a gradient especially when safety is critical.
Because they advertised it as a fully autonomous self-driving car, not a 96-98% self-driving car.
That amounts to needing human intervention for 12-24 seconds in a 10-minute drive, on average. Otherwise the car just…stalls? Would you buy a car that stalled irrecoverably 2-4% of the time?