Just about everything is the fault of some grammar teacher, somewhere

When the Times of London reported in 1837 on two University of Paris law profs dueling with swords, the dispute wasn't over the fine points of the Napoleonic Code. It was over the point-virgule: the semicolon. "The one who contended that the passage in question ought to be concluded by a semicolon was wounded in the arm," noted the Times. "His adversary maintained that it should be a colon."

[From Has modern life killed the semicolon? - By Paul Collins - Slate Magazine]