It (the dash ) is a comfortable punctuation mark since even the most rigorous critic can seldom claim that any particular example of it is a misuse. Its overuse is its greatest danger, and the writer who can't resist dashes may be suspected of uncoordinated thinking.
Bergen EvansSpeech is highly elliptical. It would scarcely be endurable otherwise. Ellipsis is indispensable to the writer or speaker who wants to be brief and pithy, but it can easily cause confusion and obscurity and must be used with skill.
Bergen Evans