One, the capitalists and governments of wealthier nations made it that way by military force and the drug trade, and kept it that way by military force and the drug trade, and protectionist duties, boycotts, capital flight and by appropriating resources with "hard currency".
Two, capitalists and capitalist governments never quite got the point of capitalist economic analysis, that freedom helps *people*, not just capitalists, to create wealth. Poor people are discriminated against on the grounds that they are poor, which is what keeps them that way. Some, in the more "free" countries, with insight and industry and good luck, can get rich. Most continue to live hand-to-mouth for generations.
Banks have traditionally treated poor people as a bad risk. But, if a bank chooses to work *with* its debtors, it can (at some cost) help even the poorest of them to make money -- to break the poverty cycle. Credit is a bridge to the other side of the world -- the end of poverty.
Many, many westerners donate money to charity without expecting anything (except their tax) back in exchange. Since charities are not the government and don't force you to pay them, this is seen as a "free market" deal. But charity is often worse than welfare when it comes to creating dependents. Responsible investment, OTOH, can lead to empowerment of millions of individuals, and you can expect to reap modest financial rewards as well as to feel good.
The biggest revelation to me since I have discovered microcredit is that it has been the segregation of the world's economy into countries which has kept markets non-free for so long. While globalisation is usually seen by environmentalists and socialists as a negative change for the world, it is the most important precondition for income equalisation between countries -- for as long as smug wealthy people can congratulate themselves for living in a free market, they can continue to blame other people's misery on other people's governments, instead of helping to fix it.
Regulation and/or taxation of international capital movements by the UN (or equivalent body) would end the nightmare of capital flight which compels 3rd-world governments to toe the capitalist line (i.e., permit the rape of their own countries) on pain of instant depression; uniform currency would end currency speculation.
However as long as the US remains in the hands of Democrats and Republicans with their big guns, big dicks and oil stocks, minerals will be more important than people and the profits from stealing them will be more important than the profits from allowing individuals to make their own way in the world.