When editing other authors' work or delivering unsolicited advice, I counsel fiction writers to imbue their work with realistic details. The reasons are many, but they all boil down to one thing: the reader's trust. If the reader can trust the author with the small details, then the reader will gladly take the author's metaphorical hand and trip the light fantastic into the most imaginative of realms.
Authenticity requires realism.
However, I occasionally encounter too much realism in fiction. When authenticity overpowers fiction, it may turn offensive. This distinction may also determine the boundary between authentic and marketable.
One such example comes from "dark," motorcycle club, and BDSM romances. I know some readers get a kick from a hero (or antihero) calling his one true love a slut or whore or other, even more derogatory term. However passionate, that kind of terminology immediately switches a story from authentic to offensive for me.
The man who loves me ought to know better than to call me such a derogatory name, especially when speaking to me during moments of intimacy. Men who respect women don't use such language when speaking to those women. Women who expect respect don't accept such language when spoken to them.
The same goes for racial epithets, which some subcultures routinely use to refer to each other. Using those offensive words might be commonplace among that subculture--and using those terms with a light touch adds that necessary element of realism--but saturating dialogue with such terms overwhelms.
One cannot help but wonder if the author, too, thinks in those terms.
My thoughts on the topic go beyond mere profanity. Reflecting on the way too much authenticity tips over into offense, I'm reminded of comedian George Carlin's 1972 monologue on the seven dirty words you can't say on television. (If you can't tolerate profanity, then you shouldn't listen to this.)
The saturation of offensive words and profanity in characters' dialogue demonstrates the limitations of those characters' vocabulary, just as it shows the limitations in a real person's vocabulary. Most of us have encountered the individual who uses the "F-word" every other word when he or she spoke. That person uses it as noun, verb, adjective, and adverb. Speech saturated with such words loses its shock value because we become desensitized to it. Sometimes, I juxtapose eloquent literary verbiage against the deliberate insertion of such a word to add shock value.
Desensitization to offensive and profane words does not improve our language or strengthen our vocabulary. Those whose language is so limited lose the ability to deliver or understand stinging insults or high praise without them. Like stereotypes, language informs the reader by assigning a commonly understood trope or archetype. A gangsta from the 'hood employs much different speech than a church bishop, or a noble lady from a lowly maidservant. Our use of words and the variety of words used give rise to assumptions of education and intelligence and wit.
Like passive voice, when it comes to authenticity (aka realism), sometimes less is more. Authors seeking to tread the line between authenticity and offense often dance on a knife's edge.