That rosy picture is totally divorced from the actual historical course of Capitalist development.
If the reason is ethical than why would we support sweatshop labor, or any other exploitative labor?
What exploited people need is not sweatshop jobs but access to capital and education. Invest in them, do not exploit them.
Investment in people is a red herring. You can give people choice and invest in them. Though guess what: developing countries (which is who we're talking about) don't have money to do the latter.