> People don't like that idea because it's highly exclusionary.

I disagree with you here- you have it backwards. It's cars that are exclusionary. Kids can't be around car traffic unsupervised, because car traffic is very dangerous. Old people become fat and frail only because they're robbed of exercise by a car-centric lifestyle. Blind people can't drive. Kids can't drive. Old people can't drive. By shaping cities around cars we doom the vast majority for the sake of a very small number of people, and many of them would probably be healthier and safer getting a little exercise and enjoying the excellent public transport that results from shifting a massive budget for car infrastructure to public transport.