I think the mistake you're making is implying that bad working conditions are inherent to a poor nation, and good working conditions are inherent to a rich nation, so the ends (good working conditions in the future) justify the means (bad working conditions now). Might it be possible that america becoming rich and america getting better working conditions were not causally related? It seems to me that better working conditions came out of labor organizing, rather than a natural result of wealth increase.
All countries that have gone through development started with bad conditions that got better, not just America. China is proof of that right now. You could just as easily condemn the people you would otherwise want to help to poverty instead.
