Ok I want to say a couple things,
One of the underlying principles of economics is scarcity. The fact that it exists is perhaps the only not-as-debatable principle of economics, which is considered a rather sketchy science considering a lot of predictions made by "expert" economics end up entirely off the mark. So yes, you will always have your rich and your poor.
However, just because you will always have your "poor" doesn't mean the standard of living cannot be raised. Most poor people in America can still afford to buy a dollar menu meal at McDonald's. A lot of poor people in other parts of the world cannot.
Yet there are ways to improve the standard of living in such places as well. For example, it only costs around $1000 to open a school in Africa. This was accomplished by a girl in my high school class and her mother. $1000 is not that much money for an American compared to the impact it has on education. Other good programs out there to look into are the One Laptop Per Child and Kiva.org, which I won't really explain b/c this post is already going to be pretty long.
The problem isn't money, it's people who care. True, opening a school may only cost $1000, but it costs much more than that it time and patience because it also involves talking to the people and future students there and gaining their trust as well as the dedication to keep following up to make sure the school as a steady income of supplies, etc. "Don't give me money, give me passion"--in the words of a man who is trying to bring wind energy to Rwanda with whom I'm facebook friends with.
As game designers, we may not be able to put money into peoples' pockets, (esp since we're mostly taking it out
) but we can design games that motivate people, or at least make them more aware of the major issues in the world (check out http://www.addictinggames.com/oiligarchy.html
for a simple game that deals with the oil crisis).
All in all: We can't make a perfect world, but we can definitely make a better one.