that's not a very compelling reason. Making it slightly easier for you personally to carry your groceries isn't going to convince anybody that personal vehicles are a necessity.

>Why does the car debate need to be made into some kind of class conflict?

because it's simply not sustainable for everybody who wants to drive a car to do so. there isn't physically enough space. The only way to let some people drive a car is to make it expensive enough to discourage most people from driving a car.