aristotle - 1:19 pm on Oct 7, 2012 (gmt 0)

Matt Cutts realized that all of his efforts over the years to stop spammers had mostly failed, and somehow finally concluded that the only way to really stop them is to bring down any site that might have had SEO applied to it or its backlinks. Penguin is the result. But since it is based on a false premise, its main effect has been to lower the overall quality of the Google SERPs.