The reason zoning in the US requires developments to take cars into account, is that people in the US want cars. And if someone builds a new residential or commercial development that doesn't recognize this reality, it creates problems for everyone as people have nowhere to put the cars that they definitely want to use.
Yes, there are some people who live in cities and are happy to have the entirety of their life limited to the region they can walk to, or the places where government-organized mass transportation can deliver them like cattle. But those people are the vast minority. Everyone else wants a car.