I was thinking they should have just made a single key for that.
 

 
Then I found this PCmag article from 3 yrs ago...
 
"We could've had a single button, but the guy who did the IBM keyboard design didn't want to give us our single button," Gates said. "It was a mistake... We did some very clever things", Gates said, but Control+Alt+Delete was not one of them.
 
The guy is David Bradley. "I may have invented it, but I think Bill made it famous."