Source : Free On-Line Dictionary of Computing

dumbed down
     
         Simplified, with a strong connotation of
        *over*simplified.  Often, a {marketroid} will insist that the
        interfaces and documentation of software be dumbed down after
        the designer has burned untold gallons of midnight oil making
        it smart.  This creates friction.
     
        See {user-friendly}.
     
        (1995-04-14)