It matters to the safe drivers. Bad drivers are mostly a danger to themselves. At only "1.5x as safe as average", it's a good deal for the bad drivers, but there are probably a lot of "2x as safe as average" drivers that are getting a bad deal. They are in more danger than before.
Edited for clarity.
In the past couple of weeks, I've narrowly avoided hitting pedestrians three different times. Each time, the pedestrian was somewhere other than a valid crosswalk (once was on a highway exit). In each case, I think an autonomous vehicle could have handled it better than me.
A perfect autonomous car sure sounds nice - but will it ever arrive? Would it have just hit 1 of those pedestrians instead? Would it just go, ding, and suddenly you're in control? Would it kill 1 and then the company would have the data to know to not kill pedestrians in that one specific example? How many people would have to die as test subjects before the system would be better than people? And what if it never got there but you still killed all those folks anyway?
And tesla's system is unable to see stationary objects. It would never qualify as an autonomous driver.
We don't need a perfect system to avoid hitting pedestrians. Current tech can actually do a good job. It just has to be a design goal of the system.
Source? It seems only logical that the number of accidental deaths goes up with the number of bad drivers on the road - not just because they kill themselves.
My point is that, even if we lower the total death count, the safest drivers could still end up at greater risk, because a disproportionate amount of the reduction in deaths will go to bad drivers.