When I first started reading fantasy in the early 1990s it was pretty tame stuff. The violence was nothing you wouldn't see in a matinee adventure movie. Swearing was typically mild and restrained and sex, if it happened, was minimally described with writers usually employing the tried-and-tested fade to black transitions.
Enter George R.R Martin, whose Song of Ice and Fire saga was as disruptive to fantasy writing as the spinning jenny was to the textile industry. Martin gave us a visceral depiction of humanity and society with characters that 'could eat the Borgias'.
It's referred to in the trade as grit. In places, Martin treads a very fine line between grit and gratuity; no subject is too taboo for his graphic writing, there's sex and violence aplenty, a lot of it performed on and by children1.
Thanks to Martin's success (on paper and television), a lot of writers have followed suite and a new subgenre, Grimdark has emerged. Grit and realism is in and it sells books -- tonnes of them. By contrast, the classic high-fantasy post-gothic romance of Tolkien or the whimsy, satirical genius of Terry Pratchett seems like a quaint anachronism.
The success of Martin (and similar authors) has made Grimdark the new normal. Writers looking to make an impact try to outdo the last successful franchise with even more literary shock and awe. The mainstream appeal of Game of Thrones tells publishers that readers want sex and violence; the more graphic the better.
The problem for many readers, myself included, is when grit becomes gratuitous.
Gratuity is a difficult concept to define but it's a potential pitfall for every genre and every medium of story telling. Detail in itself is not gratuity, be it the actions of a sadistic character or a moment of passion shared by two lovers. Detail's job is to colour the elements of narrative. I'm not against detail, even when used to describe events that are confronting; good writing must have an impact.
Gratuity, in my opinion, is defined by the author's intent. When events are depicted in a way that is intended to titillate or shock the reader, rather than drive the narrative, then it has become gratuitous. When that line is crossed, the writer risks losing the fundamental goals of narrative fiction and ventures perilously close to pornography. Readers then aren't there for the journey and the catharsis it brings, but have become voyeurs, vicariously living out their own fetishes through the ecstasy or suffering of others.
HBO made a lot of changes to various character ages and avoided many of the more taboo scenes to make Game of Thrones less confronting to our modern sensitivities. Daenerys Targaryen for example, was only 13 when Khal Drogo took her virginity, certainly nothing like the voluptuous 30-year-old Emilia Clarke who plays her character in the television series. ↩