Whether we’re talking about heavy metal music or science fiction or alternative comix or anything else, genre is a conversation, an ongoing back-and-forth. The best genre works aren’t “timeless”– they are very much of a particular moment in the history of the genre that gave them life. They build upon what came before, and point to what comes next. That is exactly what we respond to and why we like them. What’s good about a good genre work is often the way that it bends or breaks the conventions it is supposed to abide by. That particular way of bending and breaking then becomes a part of the genre.
That is why someone new to a genre may have a hard time appreciating it. How can you understand Star Trek without knowing Heinlein, Limp Bizkit without Loverboy, David Foster Wallace without Raymond Carver? Sometimes the new thing is an extension of the old. Sometimes it is a rejection and a negation. But always it is connected to, and dependent upon, what came before.
Yes, I include “literary fiction” as a genre.