When gothic literature first burst onto the literary scene in the late eighteenth century, it was the subject of widespread contempt and derision. For one thing, there was a certain excess about the gothic, both in style and content, that offended the refined sensibilities of the adherents of the Neoclassical school, who prized decorum, order, and fidelity to nature above all else.
Gothic literature, with its general air of moral ambiguity, also offended the values of those who looked for clear-cut moral lessons in their reading matter. The dominant taste among the reading public was for tales of moral uplift, in which good always triumphed over evil and virtue was its own reward. And yet gothic literature went against the grain by presenting the eternal battle between good and evil in far less one-dimensional, more sophisticated terms.
In Bram Stoker's Dracula, for example, we have a title character who is the epitome of evil. And yet at the same time, there's something strangely attractive about the Count. On the face of it, he appears to be an urbane, sophisticated aristocrat devoted to retrieving his ancient family's long-lost glory days in Transylvania. This makes him rather sympathetic in a way that a vampire in a more lurid, more sensationalistic horror story could never manage.
By revealing a lot of backstory about Dracula's family history, Stoker places the Count and his evil firmly within our world. Dracula may be a blood-sucking vampire who regularly turns into a bat, but he's also a European aristocrat with a more than respectable lineage. This makes his evil all the more ambiguous and, by extension, more frightening, as it is part of a world with which we can identify, even over a hundred years after the book was written.
Of course, the way in which Count Dracula goes about compensating for his family's lost power is morally unacceptable, but there's no doubt that his motivations are still recognizably human. This is what makes Dracula such a fascinating character and allows us to see in him something more than just a blood-sucking monster.