The seasons are frequently described as unpredictable, but over the course of the novels it's suggested that in recent living history they have become elongated

The seasons are frequently described as unpredictable, but over the course of the novels it's suggested that in recent living history they have become elongated. Imagine the effects that a 9-year winter would have on a population. It's possible that these seasons are a part of a cycle where civilization builds up, and then is decimated, which would be a huge hindrance to technological progress.