The yin of vodka. The yang of orange juice. To tighten you up for a job interview. To loosen you up for a hot date. This is the drink for man on the go, the working man with a screwdriver in hand (according to lore). A screwdriver is indelibly associated with the American aviator.
A peanut butter and jelly sandwich has similar legends. The PBJ provides pilots with a handy and tasty composite of necessary nutrients. And so with the screwdriver. Everything you really need, palatable enough, and easy to rustle up in a pinch.