This is a real and scary problem. It is not without precedent--the horrors perpetuated by the unfettered corporation-states during the colonial era are an example of the results of 'self policing', which is too often society's answer to how corporations should be regulated.
This makes for a situation that is worse than that faced by the first rounds of Industrial Revolution countries, for labor movements have little power when economic benefits actively bypass countries with more regulations and flow to the most corrupt and exploitation-friendly countries.
Perhaps we cannot (yet) create a utopia where every human who is born has a healthy and labor-light life. But we can refuse to accept the 'actual realities' and try to prevent scenarios where wealth is distributed to the exploiters and not the exploitees.
If borders were open to labor migration as they are to capital/corporations I bet the situation would be much better.
Borders nowadays exist only for the lowest of classes. In a globalized economy borders seem like a mechanism of opression.
Just my 2c.
The problem is when the chain of supply and demand grows longer and longer (i.e. covers more distance in terms of culture, national borders, multinational markets, etc), as it does today. In the modern era, what if Henry Ford's factory was in a third world country? There would be no shortage of first world consumers of Ford's products, so in that scenario there is no capitalist incentive to raise the workers' wages. Especially since the first world consumers are buying the products for the very reason that Ford is paying wages impossibly below first world pay scales.
This scenario is also not without precedent, for what it is is the isolation and exploitation of one population in favor of another population, which is a colonialist scenario (as opposed to a Marxist scenario where classes are stratified in a single society). In such a scenario, nothing capitalistically motivated will come to the aid of the exploited population until a very long chain of supply and demand has been unwound.
Paying your workers enough to buy your own products is mathematically impossible to profit from--they're just paying you back money you paid them in the first place, and they can't pay you more than 100% of their salary, so you always pay them more than they pay you.
If only that were true. It would be an incredible improvement.
However, countries cannot simply follow other countries' recipes for "success". Unbridled optimism hurts. Economic development (not to be confused with economic growth) is not an inevitable process. There are many pitfalls and it is a constant effort to stay on the path towards economic development to reach a point where you become a developed nation and can look forward to growth.
There is no simple blue print for guaranteed success. What worked for South Korea might not work for Bangladesh.
People aren't "justifying" anything, they're stating actual realities of the world. 30 years ago South Korea was the sweatshop of the world. Today it is an economic powerhouse with largely first world living conditions. The same is increasingly true of China. Countries don't just skip that stage in their evolution, short of some mythical utopia project, however much we might like to think they can.