That's the whole point. People do not voluntarily work for shitty wages at shitty jobs, they are forced by the need of money.
Workers in western countries are extremely lucky, since they live in very wealthy countries where even the shittiest job usually gives the possibility to live a decent life.
However, I'm not sure (to make an example which is extreme in the opposite way) congolese children do voluntarily work in cobalt mines, getting intoxicated and often dying just to be able not to starve in the short term.
Regarding the rest of your comment, I just have to say that:
1. yes, people can start their own ethical corporation, and some people actually did that. But they are pretty much irrilevant in the global market. Actually, I would argue that following ethics often puts a corporation in a less competitive position.
2. just because I could do that myself doesn't mean that's a good thing. I'm not saying that the capitalist class is evil and trying to destroy the world, I'm just saying that the system is flawed in allowing such a restricted pool of people to accumulate so much wealth, and to actually encourage the exploitation of people and resources in order to stay competitive.
True, because most PEOPLE don't care about exploitation. Or can't afford to care if they want to keep their living standard. Thats the problem. That's my whole point, corporations just produce what people want. And most want it cheap.
And yes, the system is flawed, because people are flawed. Change one, and you change the other. Hard? Now thats news ...
But I think many things are changing for the better. So we are on a good way.
And you do realise, that there are many different kinds of corporations? And even in the most shitty ones, people choose freely to be part of it (even if pushed by money pressure).
And again, you are totally free to gather fellow "workers" and start together a corporation of the type you like and produce what you want. And people are doing that btw. Just like <people> choose to put waste in the rivers, or not.
It is allways people doing things, good or bad, bound to a corporation or government or whatever other group. Just picking one type of organisation and blaming everything bad on it is extremely oversimplifying and I can't imagine how that could improve anything