I understand what you saying but you could use the same argument for the old triangular trading, that was heavily reliant on exploiting poor economies and its citizens. I'm not comparing what some young footballers go through as anything like slavery! But there are group of people who see echo's...
Yes they get fantastic money but there is an opinion in football that players are treated like a commodity; especially the young and vulnerable players from economically or socially ravaged countries. At a dinner I think it was called "black business men of the year" it was attended by many...