I recall once looking at a sample chapter from a novel, and there, in the second sentence of the opening narrative, was the dreaded, F-bomb. That was it. I was done. The book may have had an intriguing title, but once I saw that expletive I was immediately turned off and had no reason to read any further.
Now I'm not saying I'm a total prude, and for some genres this kind of language may be both suitable and expected, but not for my work. I write contemporary sensual romance. In my genre there simply is no reason for profanity, and most romance authors don't use it, especially when writing in the third person. To me, profanity, especially when used in the narrative, a sign of a lazy, sloppy writer, and a rank amateur. A good storyteller doesn't need to use profanity. Plain and simple.
Some of you may be asking, "But what about the dialog?" Sure, there will times when an, "Oh my goodness gracious me," simply won't cut it. I'm also fully aware that it's the 21st century; not the 1950s. Therefore, I'll use an occasional, "damn," "hell," or similar verbiage in my dialog, but never the F-bomb, or any other vulgar synonym for human genitalia. And the keyword here is occasional, as in, infrequently. My characters are not potty mouths. Even my villains have more class than that.
Only once have I had an occasion when a stronger word may have been expected. That was when a character had just learned that her husband had been kidnapped. She's understandably upset, and her response is, "What the ---?" She's then interrupted by another character before completing her sentence. Some readers may have interpreted it as, "What the hell?" Perfectly appropriate for the circumstances. Other readers, however, may have interpreted it differently and assumed she was about to say an entirely different word. Point is, I left it up to the reader to decide.
Sure, it may be the 21st century, but there are still plenty of people out there who find profanity, particularly the F-bomb, offensive. So why risk alienating potential readers who would have otherwise loved your book?