Man I think you're really confused about what the "safety score is". Here it is stated a simpler way:
Tesla tracks driving style and gives you an insurance rate based on those driving habits.
My insurance rate is about $90, which is the lowest the rate goes, because the things it tracks (following distance, for one) corresponds to a lower liability risk for the insurance underwriter, which in this case, is tesla.
The monthly price is directly correlated to driving habits. You seem to be getting confused about "safety score".
I'm genuinely confused as to what about this doesn't make sense to you.
Tesla is the underwriter. They give a monthly premium based on driving habits.