So, I get where you're coming from, and it might make sense for an Aussie, who's consumer protections are very strict. However, most of what is being discussed exists in a completely different environment.
That being said, when you work for someone, it is your choice. However, for the sake of understanding the situation, let's say that companies in the local area all pay very little. Perhaps enough to pay rent, food, and utilities, but not much else. Now, you might be aware that the products you sell are being sold for much more than you make. This isn't a fair pay, and you know that. According to your other statements, you should go find a job that pays well and treats you with respect, right?
But that's based on a premise that that job and company exists. If the current jobs that aren't paying you fairly are all that exist around you, that idea falls on its head. So what do you do then? Not work? You can't afford to save with your current income, and you will starve without it (I cannot stress this point). Move? This article should be telling (https://myelisting.com/commercial-real-estate-news/1334/most-and-least-expensive-cities-states-to-rent-compared-to-income/). No place in the US is going to change your situation, as you're more than likely going to end in a worse spot, if you move without any savings, even with another job lined up. If your next argument is to move out of the country, once again, how would you do so without any savings? Sure, there are people who manage to do it, but immigration in any country is not a quick process, and employment isn't always guaranteed for unstable citizens like immigrants.
So, left in this situation, we are left to ponder the initial question; are crimes of greed (I haven't even gotten to discussing what exactly this might entail) actually worth codifying into law, and having criminal penalties attached to them? I say yes, for many reasons. Crimes of greed are typically what we perceive as immoral or damaging actions due to either unchecked, rampant white collar crime, or the actions of companies that previously would have been unthinkable, but due to eroding regulations and dulling the fangs of the enforcement of surviving regulations, the risk is mitigated enough to justify the profit of these 'greed crimes'.