The em dash is a popular punctuation mark. Too popular for Noreen Malone’s taste, anyway.
Its overuse mars efficient writing, she wrote in Slate.
“The problem with the dash—as you may have noticed—is that it discourages truly efficient writing. It also—and this might be its worst sin—disrupts the flow of a sentence. Don’t you find it annoying—and you can tell me if you do, I won’t be hurt—when a writer inserts a thought into the midst of another one that’s not yet complete?”
She hasn’t been a life-long anti-em dash user, but was forced to switch sides after admitting to herself that she had a problem.