I'm not sure that I feel this guy has much of a point. He got to do something he loves for $11 an hour, when many people are taking any job they can for minimum wage. I know it's a false equivalency, but the real point is there wasn't some big conspiracy to keep him down, he just didn't really like the conditions (common, vague problems - a couple crappy coworkers, some bad management, phony atmosphere) and he didn't get the raise he wanted and didn't get hired full time, when neither of these were promised. I sympathize, but this also smacks of entitlement.
Organizing is probably a good idea, there are already freelancer unions out there. But is that going to fix temps not being treated like employees who have been there for years, or make them more likely to be hired on?
I'm not saying we shouldn't all work together to make a better workplace for workers of all stripes. But this guy just doesn't seem to have much to complain about.