Susan Bickford is only describing a basic human functions that occur in every society in the world - even the third world countries. Humans tend to separate and divide and exclude and isolate each other, we do it all day long in explicit and implicit ways. Susan is saying nothing new and she seems too nieve about the issues she brings up.
It will take a world wide cataclysmic epiphany before the USA or any country becomes a true democracy. We will get there somehow but the human condition is not truly ready to be loving enough to be inclusive at the level Susan wants.
Susan's is correct: we should be more equal with all peoples, our built environment should reflect a democratic nature or perhaps our public spaces should at least reflect the myth of our societal ideal but she does not point to the answer however impossible it may be, Susan only says, "it requires an inhuman amount of imagination to have a genuinely democratic public". Perhaps she should read some and insert those peoples suggestions for the remedy... I have one remedy... everything we see is the result of our thoughts, there is no exception to this fact so we must change our thinking.
We must start to promote altruism, courage, virtue, eternal values and reward those who are able to manipulate these notions into physical form. "We are the consequence of our mind-set and behaviors and of the institutions associated with it - the industrial society paradigm which brought great benefits in the past now create problems faster than it solves them. The world macro problem will be satisfactorily resolved only through fundamental change of that mind-set" (Willis Harman).