The record of WTO dispute panels is a record of linkage. The WTO has overruled and pre-empted laws and regulations in many countries designed to protect workers' rights, the environment, or public health. The question is not whether there will be linkage, but what form of linkage we will have. A critical step to strengthening the ILO is to remove the power of the WTO to block enforcement of ILO conventions. But they should be held to some standards, especially for goods that are exported to developed country markets, often by corporations based in developed countries.
Today there are effectively no standards.
If people in a country democratically decide that they wish to produce for their own consumption through the use of child labor, and violate no international agreement to do so, and if no foreign corporations or investors are involved in such production, there may be little that anyone outside of that country has to say about it. But if such a country produces such goods for export, it is a different story. Consumers have rights, and they have obligations. If a consumer thinks that children should be in schools and not in factories, she has an obligation to avoid purchasing goods produced by children. This includes an obligation to support laws barring the import of such goods.