Sounds like at least some of what you've been reading was heavily influenced by modernism, in which (if I understand right) elements such as plot were thrown out the window. SF writer L. Sprague de Camp once recalled asking a college writing professor about plot, setting, and characterization. The professor sniffed, "Oh, you're talking about 'good story.' We don't teach that here." Postmodernism sought to reintroduce some of those elements without losing the "literary" flavor of modernism (again, as I understand it, which maybe I don't), but maybe it didn't always succeed?

Anyway, here's one excessively common theme--probably not a trope as such--that irritates me: "All religion is evil. Always. Without exception. Although, sometimes some of the art is nice."