Trollope's famous disdain for plot

In what is certainly the must famous or at least the most unconventional paragraph in Trollope or maybe even in 19th-century literature, about a third of the way through Barchester Towers Trollope tells us in so many words: Don't worry, this character is not going to marry the odious Mr. Slope. This brings any reader up short: what, the author is creating his own spoilers? Who would do that? But T goes on in this paragraph (or maybe it's 2 grafs) to disparage authors who care too much about plot and scoffs at readers whose joy on their reading would be quashed if the plot details were foretold rather than simply foreshadowed. OK, well readers do like plot, and that's especially so for readers of genre fiction (mystery - which are entirely dependent on the mechanisms of plot) and romances (half the fun is figuring out how the characters will happily pair off at the finale). But what about literary fiction? Trollope's observation about his own peculiarities as a writer (and reader) seem fair and on point to me; as I've noted in several recent posts, we don't read T for his lot or narrative: how could anyone today possibly give a damn about a dispute involving 19th-century Anglican church doctrine? The stakes were low then, and lower now. In Trollope, what keeps us engaged is not how much we care about these matters but how much the characters do - the plot is simply like Hitchcock's "McGuffin," a device to animate the characters of the novel. His novels are about people and relationships, not about events, crises, or even ideas.