To be fair, as someone who dabbles in the industry, production unions are awful and a large reason why budgets are so ridiculous. Non-fiction media in particular rarely uses union members, because it makes it very difficult to be flexible and adaptive in the field. I was just traveling with a cable television show, and the guys they use are contract, non-union hires. They couldn't afford to produce with union guys, and the logistics would be insane.
Not to say that Moore isn't being hypocritical, because he certainly is. It's the same reason why he seems to link layoffs to GM's bankruptcy, and glorifies the creation of the auto-workers union without any of the realistic analysis of it being part of its very industry's demise.