"The tendency to focus on the short-term rather than the long-term implications of our actions." 1
In other words, we place a much greater emphasis on immediate rewards rather than future rewards. As Robert Myer and Howard Kunreuther explain in The Ostrich Paradox, a dieter will go for the dessert even though he'll regret it the next day. The portion of the brain that controls the primitive instincts, the limbic system, kicks into gear and will generally overwhelm the prefrontal cortex which would consider the future rewards.
Simply put, most of us are wired to behave in this short term way. This bias also shows itself in economic activities. A dollar today is worth far more than some future value, even if that future value has a high return. The result is that people, governments, and institutions of all sorts delay spending money today on protective action. The evidence of myopia bias is everywhere, despite the proof over and over again that spending today can have an extraordinarily high value impact for a future high consequence event.
There clearly are those who spend much of their life calculating the value of future events, such as bankers, insurance professionals and climatologists. Many individuals do this as well; it's probably safe to say that people with a go bag or emergency kit, or a plan fall into this category. Unfortunately, according to a study published by Columbia University, upwards of two thirds of Americans feel they - and their local governments - are unprepared.
1 - Meyer, Robert. The Ostrich Paradox: Why We Underprepare for Disasters (Kindle Location 219). Wharton Digital Press. Kindle Edition.