Obviously, that's a storytelling modality that works very well. One can hardly argue with the commercial success of either Lord of the Rings or Harry Potter. Either of those series probably moves more books in any given month than I'll sell in my entire publishing life.
Humans, or at least humans living in the storytelling and cultural traditions of the West, have a strong affinity for dualism. Perhaps we're all birthright Manichaeans. The simplicity of moral contrast, of a binary choice, appeals strongly to us. Many people distrust nuance in ethics, in morality, in politics, in law. There's something very comforting about a simplistic good-vs-evil dynamic. You know who the "us" are, and you know who the "them" are. And certainly in both Lord of the Rings and Harry Potter, that is unambiguous on the page.
Yet there's a gentleman down in New Mexico who's shifted more than a few million books writing about a world where the good guys aren't very good, and most of the bad guys have mixed or even noble motives. Kind of like real life, where everyone is a protagonist, a hero of their own story. George R.R. Martin's A Song of Ice and Fire has proven in a big, big way that you don't need stark moral dualism to sell well. Damned near everything in those books is ambiguous. There is still a decidedly strong moral dimension. It's just ambiguous and complex to the point of being non-Euclidean.
So I think about my own work in this context. Most of my books don't have clear-cut, central antagonists. (Well, maybe none of them do.) My plots tend toward one of two models — the hero(es) opposed by a shifting collage of shadowy forces; or a set of interlocking protagonists with conflicting goals. I like what I write. Bluntly, if I didn't like it, I wouldn't write it. But I don't write like Tolkien or Rowling. Or Martin, for that matter.
I write like Jay Lake. And Jay Lake is a guy who sees the world as complex and nuanced, and largely filled with people who think they're trying to do the right thing, even if too many of us cannot see the consequences of our own actions and beliefs for what they really are. (Yes, that's a not-very-veiled reference to contemporary American politics, but it also really is how I see the world in general.) So I write fiction where the world is complex and nuanced. I don't think I could write a Sauron or a Voldemort. I just don't believe in pure evil for evil's sake, any more than I believe in pure good for good's sake.
So, no towering antagonists for me. Which makes me wonder about Sunspin, which is decidedly in the vein of interlocking protagonists. Much as the precursor novel Death of a Starship was. It also makes me wonder about my sales figures. Am I really writing stories people want to read? Or am I doing it wrong?
What do you think? Do we need Sauron and Voldemort? Or does George R.R. Martin have the right of it? Where do you fall as a reader? Where do you fall as a writer?