Put simply: The existence of motor vehicles is good, from most perspectives. It's fairly hard to argue they're not.

The development of cities caused by unrestricted, broad private car ownership without lots of careful coordination on that development, is in the reverse situation: it's fairly hard to argue it's net-beneficial, because it's so incredibly expensive in all-told money, time(!), liberty(!!), and, if we'll allow consideration of such things in a basically-economic analysis, pleasantness of environments for humans to exist in.