It is mostly we hold automated machines to a higher standard. If 5% of all flights would not arrive would you fly?
If human pilots had a 15% error rate, and autonomous planes had an error rate of 5% - which would you fly? It's basic math - you pick the one that is most likely to get you there safely.
Most people have no issues getting into cars - despite the fact that they're one of the largest killers. So we've already established that for most people, the convenience (or their love affair) of cars is enough to overcome the current risk of death/injury - if we could decrease that, is that not surely a net win?
Neither.
I'd want autonomous cars to be a lot safer than the average human driver before they were allowed on regular roads without a human behind the wheel. In fact, given that humans and machines are likely to make systematically different errors such that the human can solve most of the driving issues that the machine has and the machine can solve most of the driving issues a human has, the case for getting rid of the legally-responsible human driver altogether (humans ought to have the right to be drunk or sending emails whilst in their own vehicle; taxis ought to be cheaper?) isn't particularly strong.
You're making a subjective judgement that humans are fundamentally less safe than autonomous drivers.
Like most HN commenters you are making this assertion without any facts, as there isn't sufficient data to make the assertion. Other than drunk driving diversion, the case isn't as clear cut as you may think.
If you want to reduce fatalities, reducing SUVs and drunk driving is the end goal, as rollovers and alcohol related crashes are the most preventable fatality sources.