Our view has been one of idealism, we do not deny that, and a hope that harming the economic might that underpins the removal of liberty in the third world can help to bring about the end of that system. The critique often levelled is mixed: on one hand there is the fair point that these people may earn very little, but what they do earn feeds their families and such a boycott would harm them; the second a far more insidious ultra-capitalist position of they should be grateful for whatever they can get and the bosses have the right to do what they want.
The latter, let's not delude ourselves, is the ultimate propertarian position. The boss owns the land and the factory and he pays the wages, therefore the workers may be practically slaves and live in grinding filth and poverty with zero liberty or rights, but it is the bosses right. If they don't like it, they can quit - presumably to starve to death somewhere - or they can rise up.
These people are already starving. They have been struggling along as subsistence farmers since forever. This job is an improvement on their lot, one they have a) voluntarily taken and b) probably fought hard to get, since supply is much greater than demand.
They don't need to "rise up" and revolt against their employer. They can simply go back to subsistence farming. But why would they, because it's an even worse life than what they have working in a factory?
These people already were slaves, slaves to their families, slaves to poverty, slaves to a lack of any chance of a better life. This awful, soul-destroying job is their first step to economic and social freedom. It's an awful existence, but crucially, it's better than what they had before. If it wasn't, they'd simply go back to subsistence farming.
Unlike idealists, this old cynic looks at outcomes. I would far rather someone got richer, healthier, lived longer and ultimately became freer through my callous heartlessness, than that they starved because of some idealistic bell-end.
Remember, kids, these guys are taking these jobs voluntarily because the jobs are better than any other option they have. Wages are low because there is vastly more supply than demand for the workers. But for all that, it's still better than what they had before.
You can rail about the heartless über-capitalist, but the capitalist is the guy who decides where he spends his own money. And the rational thing to do is to maximise your return on investment. If he chose not to invest his money in Outer Cuntistan, those people would continue their shitty lives scraping by an even worse existence off the land. And if you're going to start with minimum wage or any of that shit, he may still bother because he's a really nice guy, but crucially, he may well fuck off somewhere else.
Your noble ideals will have doomed Outer Cuntistan to another generation of desperate, grinding poverty and misery. But since your heart is in the right place, you can feel good about it. It is your right to feel good about people being worse off, kids dying, people being denied the chance to a better life. No, really, it is.
Motives trump outcomes, every single time, especially for social democrats.