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If nobody is reading these articles, no-one cares about the link contained therein. Therefore why would Google care and promote your site based on that link?
As much as the modern day relevence of pagerank is debated, this is a classic example of what the PR system was fundementally designed to filter out.
Also I wouldn't be surprised if many of the big article websites haven't been filtered out manually as well, as they are essentially just big old spam directories.
Bottom line the perception is they still provide juice to a site so they will continue to flood the results.