For example, lawyers write. How is it possible for this person to develop their writing? Typically in law school, you spend an entire school year in one class developing your legal writing. Writing briefs from scratch for your professor, so he can IN DETAIL explain what you did right and wrong. Do you think a firm is going to invest this time in such an individual? I don't think that is a likely circumstance.
Nevertheless, what you describe is essentially an internship, which law students typically do their 1L and 2L summers. Oddly enough - the minimum wage has nothing to do with it. They are jobs where you are either working at a large firm and getting compensated at the same rate you would as a full time(180k a year - not too shabby for a fresh grad), or you are working at a smaller firm and probably for free... Nowhere is the minimum wage getting in the way.
I can see why the other poster kept taking up the issue with you. I can't imagine an actual situation where it's as you describe.