Why Are EM Dashes So Inaccessible?

The em dash may be the only basic punctuation mark that has no home on the keyboard. I use them far more often than parenthesis, but the parenthesis lands two keys on the qwerty. To place an em dash in a document--if you can do so at all-- one must discover some complex key combination to press concurrently--always different across various programs. When no such combination is available, or one can't find it, one must leave it to the imaginations of readers to conjoin two adjacent hyphens and apprehend the intended syntax--quite the aesthetic loss. An injustice to English punctuation has been committed in kidnapping the em dash.