I didn't actually vote in this poll as there is not option for "other".
The answer is simple and can be summed up in one word; GREED.
From
http://en.wikipedia.org/wiki/Greed:
Greed is the inordinate desire to possess wealth, goods, or objects of abstract value with the intention to keep it for one's self, far beyond the dictates of basic survival and comfort. It is applied to a markedly high desire for and pursuit of wealth, status, and power.
As a secular psychological concept, greed is, similarly, an inordinate desire to acquire or possess more than one needs. It is typically used to criticize those who seek excessive material wealth, although it may apply to the need to feel more excessively moral, social, or otherwise better than someone else.
Greed of workers wanting more and more for their labor.
Greed of busniness owners to have more and more profit
Greed of people who want to do nothing but have the government provided more and more
Greed of people who want more and more luxeries and thus overuse credit to obtain what they are unwilling to save to get
Greed of groups who wish to display their superiority over other groupings which causes friction and violence
Greed of people who want the government to hand out more and more entitlements
etc, etc, etc... Greed, Greed, Greed...