I just assume every single anti-car extremist lives in a place that either has good public transit or could have good public transit.

In swathes of America (and Australia, and even parts of Europe), the population density is too low to make public transit feasible and cars cease to be a luxury.

(Note: I am 100% in favor of improved public transit options and also increased investment in long distance train travel. I also don't own a car. But I have been places where you do, in fact, need a car).