At Techdirt guest blogger Chas Edwards writes that the problem with content farms (and by content farms, let's be clear, we mean Demand Media) is about ownership. "Even if Demand Media keeps most of the money they’re making from their websites, they might dodge the Google bullet if they can improve content quality by giving their contributors a sense of ownership over what they create."
I think it's about the motive. The desire to create (and share) good content is motivated by knowledge, enthusiasm, passion. The writers on the content farms might occasionally, by sheer statistical accident or serendipity, be asked to write about something that moves them, but generally the motive is pure profit. The farm identifies a content niche that it wants to fill because people are searching on that term right now. The writer gets paid a tiny amount of money for knocking out a few hundred words that are just good enough to fill that need (see here an account of one writer's summer on a content farm). And so, necessarilly, the average content is poor because the motive is poor.
Photo by Steven Ashman on Geograph.