Firstly, that's an assumption that not everyone shares — there are alternative solutions to mass transit. Secondly, even if you, say, accept that driving across medium distances — across the city, but not to the corner shop — is a "good thing", that just means that there have to be some large transit roads, intended only for cars; residential streets could still be freely used by pedestrians, either with very stringent speed limits or no car access, at all.
Firstly, that's an assumption that not everyone shares — there are alternative solutions to mass transit. Secondly, even if you, say, accept that driving across medium distances — across the city, but not to the corner shop — is a "good thing", that just means that there have to be some large transit roads, intended only for cars; residential streets could still be freely used by pedestrians, either with very stringent speed limits or no car access, at all.