Upload & Sell: On
I guess where we disagree is that I do see it as training. The ad in the original link offers photographers experience working in a professional environment without pay. You and I already have experience working in a professional environment, so it would be silly of us to work for free unless we wanted to do it. But for someone who has never shot in a professional environment before, this type of opportunity can give them experience without some of the risk (for the photographer and the employer) of jumping in head first to a paying gig.
It's not training like McDonalds trains a new employee on working a fryer or building a Big Mac, but neither was my college internship. They didn't train me to do anything specifically. Rather, they provided me with the opportunity to experience the way a business operates; the strategies, decisions, challenges, etc. But that's training nonetheless. I use things I learned that semester on a weekly basis in my own business. And that's precisely why good business schools require internships.
I just can't see how having the opportunity to work, unpaid, in a professional environment is detrimental to an unexperienced photographer. If you don't need the experience or you don't want to work for free, it's not like these companies are forcing anyone to work for them. They're providing an opportunity. If you think it's a bad deal, that's fine, and you might be right for some folks. But I think saying that these companies are predatory or that the photographers who do choose work with them do not benefit from the experience probably shows a lack of perspective. Are these types of companies cheap? Sure, but so are many of the companies that provide internships to business schools.
I'm not trying to pick an argument, just trying to provide a different perspective on the subject.