You should want to sing “the end” from the rooftops, not vomit in the sand between the back of a portaloo and someone’s million-dollar Cape Cod-style McMansion.
The why factor tells reader things about your characters. Readers learn who people, and they connect more deeply with the story, such as in “The Gift of the Magi” when writers show instead of tell.
Copyediting programs help editors (and writers) work smarter, not harder. These are the best five programs that I’ve found (and used) for editors who are also Mac users.