You may find that due to your socioeconomic status it may be more feasible to be a one car-transit using family, but for many americans who may work two jobs with a hour break between them (or situation similiar) they seriously may only manage to be able to make their schedule work with a car. (Just an example situation)

Being car-less in America is hard, I lived in a the suburb of a main city and if I was to use transit options to get to work I would have spent 3 hours a day on commute alone. That's simply not feasible. Similarly I used to work a job from midnight to noon (and a year later noon to midnight) and there simply was no feasible transit option for such a schedule, and with the sprawling nature of the suburb carpooling wasn't much of an option either.