Because nobodyt wants a small one. A jumbo martini served in an oversized "marjumbo" glass. Originating from Tutto Mondos in Charlotte, NC by restaurant workers who enjoyed their oversized martinis.
Hey Matt the Bartender, I don't want a small drink, I need a Marjumbo!
The name for an oversized martini because...well, nobody wants a small one. Place of origin; Tutto Mundo's, Charlotte, NC. see: Matt 'the bartender'.
Why do people call them martini's? No one wants a small one, they should be called marjumbo's.