A large number of people who complain about private cars do so because they can't afford one themselves.

When you can't get what you want, you teach yourself to want what you can get and then preach to everyone else that they should want it too. This applies to many other things too beyond just cars.

It's not that the criticism of private cars isn't valid, but not having one because you can't afford it isn't virtuous. It's only virtuous when you could easily have one but choose not to.