Well, I actually used the word for people who are being or could be actively forced to stop volunteering, so I think the word was entirely appropriate in that context. I understand that people perhaps feel trapped or exploited in a very limited number of industries because the competition for the jobs are so fierce. But like I said in reply to someone else, someone can make the case that open source contributors are being exploited since they are essentially working for free, and there are companies making use of their work without contributing back. Professional programmers, one could argue, is therefore making less money or loosing out on a lot of business. But you know what? It was the open source contributor's choice under which terms he or she would release the software. I like treating other people like adults, and not thinking that I know what is best for them. As long as no one is being coerced I don't see why the government of all people (who operate from the barrel of a gun, or at the very least the very real promise of violence if you don't comply) should intervene.
If everyone picked up their friends and family from the airport, there would be no more business for those who make a living transporting people to and from the airport. Even if it came to that, should we enact laws to protect the businesses? I would argue no. Why? Because it is no one's business but mine and those I pick up.
Couldn't you argue by that same logic that price fixing between companies is perfectly legitimate, since there is no direct coercion on the buyer to consume these products? Just because there is no direct coercion doesn't mean the situation is mutually beneficial. The situation is only beneficial to companies, the workers simply don't have a choice since they need some form of experience to get a paid job.