Though they can be fun. But yes, those are the books I was referring to when I talked about the popcorn core of each genre. Authors do themselves a great injury when they use genre-specific cliches to frame their narratives. When that happens, the ending and much of the content is predetermined, so how can it really be complex and layered? It's no new problem either; late medieval writers in England relied way too much, imo, on the tropes of romance. That's why you get only a handful of really interesting literary works between Beowulf and Shakespeare.

The "genre" of tragedy forms the exception to this rule, I suppose... most of the beloved classics are formulated along those rather specific lines. I think they make it work by turning predictability on its head; instead of a quiet writerly cop-out, it's one of the central narrative themes (presented as fate, predetermination, etc.), and never an easy pill to swallow. Very clever, those ancients.

I agree, but the line is always going to be somewhat arbitrary.