Some make the argument that Google is feeding the spam problem simply by having an Adsense program. Is this a simplistic argument?
I think so.
The problem isn’t that junk content exists, or that is being generated in huge quantities. The problem is that junk content (as judged by the user) shows up when we don’t want to see it. If junk Adsense content sinks to the bottom of the longtail (to mix metaphors), and is never seen again, except by the author, then is it spam?
Google, and other search engines, need to ensure that search results return the answers the users require. Google can’t favour Adsense content, and I don’t think they do, but if the searcher is best served by Page X, then it shouldn’t matter if Page X has Adsense on it or not.
In other words, Google must always reward content that users want, and let the rest sink without trace.