It’s an interesting social commentary, on the devaluation of thought. At one time if someone plagarized it was bevause they found value in your words or ideas; value they wished to claim and capitalize on as their own.

I still think the content thieves want content that has value: they want to attract people to their site, and to do that they need some sort of “interesting” content. Pure “filler” is recognized as such by the folks who browse the web- if its true crap, visitors won’t be back. The thieves need content that’s good enough to attract visitors, but not immediately identifiable as belonging to someone “important”.

You are right, though, that there isn’t much (if any) human judgement of value. The thieves primarily look at site popularity and, as Jonathan said, they try to hit folks in the “middle class” popularity range. Once they target you, the process from then on is largely automated.