Meh. We live in a town of 12,000 people (big town for the area, but in a very rural part of the US). My wife and I share one car, and walk/bike/take transit more often than we drive--the car is mostly for getting our daughter to daycare in the winter and for when my wife is on call at the hospital. There are plenty of folks in the area who don't drive at all.

There are certainly parts of the US where a car is necessary, but 90% is pushing it. It may well be that 90% of people think that they need a car, though.