Earlier quoted context omitted.
A car being driven is guaranteed to have a person behind the wheel. (For now...) A electric car in an attached garage spontaneously bursting into flame at 2 am is a recipe for burning a house to the ground.
In the former case there's definitely a person inside the thing that's on fire, and in the latter case there almost definitely isn't a person inside the thing (I guess once in a while somebody sleeps in their car but this isn't recommended) and that seems like a much safer situation. Houses are replaceable, that's why people have insurance.
Just kidding.