Power Up the Mainframe! (Games that use painfully anachronistic computing references)

Despite some notable exceptions, mainframes are on the outs compared to distributed networks.  Distributed networks allow you to link a bunch of cheap computers and get decent processing power and relative security as compared to the old centralized computer model.  So why do so many games, especially science fiction ones, have mainframes prominently featured?  It's cuz the writers that grew up during the mainframe years, myself include, think the word has a monolithic-sounding power to it.  We probably have in mind films like 2001 from the 60's, where centralized computing was king.