The practice stopped because of an agreement reached with the Justice Department[1]. I don't know which theoretical model leads you to believe that capitalism tends to correct itself, as historical evidence suggests otherwise: that the free market tends to converge towards feudalism (in the broad sense) – as happened in the US in the late 19th and early 20th century – or crisis; any corrections in course have always been due to public uproar which led to increased regulation.

[1]: http://www.nytimes.com/2010/09/18/technology/18google.html