Google wants to provide the searcher with the most accurate and relevant results that it can. They are aware that if they do not provide this info, its likely that searchers will no longer use their services completely, and no users means no advertising revenues which is their primary source of income!
For a prime example of a search engine dropping the ball, spend a second for AltaVista? In its time it was the most popular search engine, and very quickly lost the crown to Google because they dropped the ball with relevance.