Why should it be? In the end the dead bodies count and it doesn't matter whether a cautious or inexperienced driver killed them. Inexperienced drivers are prerequisite of experienced drivers, there's no way to get rid of them. Excluding them from statistics is just discounting those deaths as... somehow less important?
If a self-driving vehicle is only 1.5x (instead of 5x) as safe as the average human driver then you're not trading between death by humans vs. death by machine, you're primarily trading between death by human and spared by machine and only secondly between the former.
If a self-driving vehicle is only 1.5x (instead of 5x) as safe as the average human driver then you're not trading between death by humans vs. death by machine, you're primarily trading between death by human and spared by machine and only secondly between the former.