I've always admired authors who can write family friendly stories. Harry Potter could never have appealed to such a wide audience if it contained sex, cursing, and gore.
I've heard time and time again that most sex scenes add very little to a story, that a novel could be just as good without it. Swear words could be substituted for other words. Violent descriptions can be toned down. The imagination fills in the blanks and can be more frightening than anything else.
Unfortunately, that's not how I write. I'm terrified of being judged for how my imagination works. For instance, currently, I am writing a novel about Medusa. First of all, writing anything at all about Medusa and her origins means including a rape scene, since Medusa was raped by Poseidon and turned into a monster because of it, but second of all, my story also includes prostitution, naked Aphrodite making out with her father, drugs, and Medusa's sisters (who are also gorgons) taking the body parts of the men they turn into stone and doing some unsavory things with them. And I'm just describing parts of the first five chapters here.
I do think there's room in writing for vulgarity and profanity. I think it can reach adults in a way that other stories can not. An example of this is the Bible, a book that has been relevant to us for thousands of years, and contains very vulgar stories.
When I was a child learning about David and Goliath in Sunday school, I had no idea that after he threw the stone at Goliath, he carried his bloody decapitated head around, showed it to everyone in the army and brought it to King Saul. I didn't know that this little guy would marry King Saul's daughter. In order to win her hand in marriage, he was forced to kill and chop off the foreskins of hundred of Philistines and offer them in a basket to her father. When David was king himself, he went on the roof of a palace, saw a woman bathing and had an affair with her. She became pregnant and David had her husband killed since he was out at war and would know that she had had an affair. One of King David's sons grew up to rape his sister (the Bible details the plot of how this was done) and when David found out, he didn't care and was almost killed by his other son, Absalom, for his callousness.
A lot of the values we practice today as a culture can be found in the Bible, yet it is filled with filthy, gory, disgusting stories.
Greek myths, we still read and love today contain tales of incest, rape, violence, and sexuality. Odysseus is certainly not someone I'd want any teenager to model themselves after, but we still read the Odyssey in high school.
I remember reading the Good Earth which had quite a bit of prostitution and sex in it. Lord of the flies involves barbarism and killing. Everyone knows what the Scarlet letter deals with.
But according to this idea that dealing with adult themes in novels is trashy, all these stories are worthless.
I wouldn't want children to read these things, but I think that stories that deal with baser human reactions and emotions, can hit adults in ways that other novels can not.
So while I sometimes do wish I could write for children, I don't regret how I do actually write. I try to give a purpose plot-wise or character-wise for most of my vulgarity and I don't think there's anything wrong with that. Everyone writes for a different audience and most adults will one day read a story like one of mine.