"There Is No Reason for Any Individual to Have a Computer" — Ken Olsen (1977)

As DEC's founder, he dismissed personal computing just as the PC market was about to explode from 0 to over 200 million units by 1999. This miscalculation directly contributed to DEC's decline, with the company sold to Compaq in 1998 for $9.6 billion—a fate that underscores how his failure to see the future proved 30% more costly than other mainframe makers' missteps.