> you underestimate that people living in wealth don't share the same degree of
> compassion

This is true to a great extent, but we cannot so easily make a broad generalization of this nature. I am not a student of philosophy, but the German philosopher Friederich Nietzsche came very close to unravelling the nature of western principles of morality. What our western society sees and good and evil.

among the many things that he wrote on the subject the main work would be "On the Genealogy of Morals".

Synopsis: http://en.wikipedia.org/wiki/On_the_Genealogy_of_Morality
Full text: http://records.viu.ca/~johnstoi/Nietzsche/genealogytofc.htm

In this work Nietzche argued that western principles of good and bad come down from a Greek view of good and evil. He wrote that our concept of good is born out of a contradiction.

On the one hand, we have good as seen by the "master" class: good is wealth, health, nobility, strength and power (like the ancient Greek heroes); while bad is poverty, weakness, disease and the pathetic (what the Greeks saw as the afflictions and curses of humanity).

On the other hand, we have good as seen by the "slave" class: good is charity, piety, restraint, meekness, and subservience (as represented in the values of Judeo-Christian religions); while bad is cruelty, selfishness, greed, indulgency, and aggression (those defects that would curse a human being into Hell). This "slave" morality arose in response to the "master" morality and has become central to Judeo-Christian morality.

In "Beyond Good and Evil" Nietzche further argued that the powerful put themselves beyond this concepts of good and evil by using their wealth and power in their own favor.

Synopsis: http://en.wikipedia.org/wiki/Beyond_Good_and_Evil
Full Text: http://www.allphilosophers.com/nietzsche/nindex.html

It explains why our world is so full of contradictions. Consider John D. Rcokefeller, the man who became (and still is) the richest man in history. On the one hand he went to build the biggest monopoly in history and threw the police to workers that went on strike in his companies. On the other hand he gave $1 billion to charity. There is a clear contradiction. Bad to his workers, but charitable to the poor. His pursuit of wealth gave him a "master" morality, while at the same time he could not abandon those "Christian" principles of "slave" morality.

We see this with other very wealth multimillionaires. That clear contradiction of principles. We also see it in our wars. Good Christians (or Moslems, Jews, Hindus, etc.) will go to war, kill thousands, and then wash their hands of responsibility on the name of higher principles of "good". They sleep soundly knowing that they will go to Heaven because "good" is on their side.