Up till now, the US, Canada, the EU and Japan have dominated the WTO, but as membership has grown, they find themselves outnumbered by developing countries, which are becoming a mite impatient at the highhandedness of the Big Boys. However, producers of rice, sugar, and beef in developed countries, among other commodity producers, are adept at lobbying. With the skillful distribution of money, they are able to make persuasive arguments for their subsidized industries. Phone a travel agent to get the price of a First Calss ticket from, say, Vancouver to Toronto, get a sense of that expenditure. Well, there aren't many rich farmers, but there are a lot of profitable agribusinesses that don't have to worry about being underpriced by anybody.
Governments pay the subsidies.
The WTO has had two recent meetings with blowups - Seattle and Quebec. It seems that people on the street can't get it through their heads that shareholders and market dabblers are more important than producers and consumers. WTO organizers are worried about people being people. But they are learning. The next meeting to try to organize the world for the benefit of shareholders will be held in Qatar.