Your examples (doctor, pilot, and driver) all involve doing things that have a minimal level of attentiveness built in. It's why one cannot perform surgery, fly a plane, or operate a car whilst drunk without facing criminal repercussions.
Making your way home from work does not have any minimal standard of attentiveness that it is considered criminal not to display. (With the obvious exception of the driving itself)
Possessing and using a lethal weapon, one assigned to you as a trained LEO, does not have any minimal standard of attentiveness, while simply driving a car does? Are you sure?
'd by G