Errol Morris on “investigative journalism”

From Errol Morris’s “Film Legend Errol Morris Salutes New Graduates At 2010 Commencement” (Berkeley Graduate School of Journalism: 10 May 2010):

I have often wondered why we need the phrase investigative journalism. Isn’t all journalism supposed to be investigative? Isn’t journalism without an investigative element little more than gossip? And isn’t there enough gossip around already?