And if I'm guilty of having gratuitous sex, then I'm also guilty of having gratuitous violence, and gratuitous feasting, and gratuitous description of clothes, and gratuitous heraldry, because very little of this is necessary to advance the plot. But my philosophy is that plot advancement is not what the experience of reading fiction is about. If all we care about is advancing the plot, why read novels? We can just read Cliffs Notes.