To be clear, Gates is referring to CTRL-Alt-Delete for logging into Windows, not the command for restarting after the blue screen of death (pictured at right). Unlike a Mac, which after booting up requires a user to log-in, PC's require CTRL-Alt-Delete first, an admittedly clunky step. But, it was that kind of institutionalization that "made it famous," to borrow the words of its inventor, former IBM engineer David Bradley. Bradley came up with the combination to hasten the reboot process, in case of things like the blue screen of death. Gates, however, forced it into the front and center of our consciousness with the log-in requirement.
And because of that fame — or rather infamy — it's a key combination we laypeople still remember today. Sure, it's remembered in conjunction with the most annoying PC glitches. But we people of Internet bloggery love nostalgia, and CTRL-Alt-Delete, thanks to Bill Gates, is chock full of '90s related memories.