The Joys of NOT owning a car!

Thanks to my dad, we have finally got the Pathfinder sold! We are now very happy non-car owners. Surprisingly, neither of us miss having a car. Over here we can walk to all over or take public transport. There are many ads every week about cheap cars for sale, but we are happy without one. Unfortunately, we will have to get a car when we go back to the States.
The lack of public transport is something that has amazed me about the States ever since I went to South America. I had heard about Europe's wonderful transport system, but I always figured it was just because everything is so compact. Then I went to Chile. My friends and I were able to go all over with no need for a car. Some of the towns with bus stops were no more than a General Store and a few houses, but the bus stopped anyway. There were flights all over too, and they were cheap too.
In Europe you not only have an excellent bus and train system, but the airlines are currently in a 'price war' so plane tickets are incredibly cheap. There are times that we can fly for less than £1 per person (plus taxes). We can even take a bus from Glasgow to London for £1 as well. There is definitely no need for a vehicle of our own.
I know that this has been a difficult adjustment for many people that come to the States to live. They come assuming that the public transport system is as great as their own country's, when in fact you really cannot get from city to city unless it is a huge one. And even then the bus, train, or plane tickets can be quite pricey
But why isn't there a better and more affordable system? It really makes no sense to me. Why would a country that boasts to be one of the best, not have a better public transport system?