Why is it necessary to understand earthquakes?

Predicting earthquakes would enable people to prepare for them. As with any natural disaster it is best to come into the situation prepared. Would you rather your stove caught fire at midnight while you were asleep or would you rather that it caught fire while you were holding a fire extinguisher standing directly in front of it? Areas that have frequent earthquakes (like Alaska ad California) are built to withstand normal earthquakes and cause minimal damage in a large earthquake. Places that rarely get earthquakes however are built with little regard to earthquakes as they are so uncommon. In Texas for example there are many "spaghetti roads" that loop through the sky and intertwine. If these road systems were built somewhere like Alaska they would probably collapse within 5 years of their construction if they were ever even finished. The Alaska pipeline is built to withstand sudden horizontal movement of more than 30 feet if a fault were to horizontally split open beneath one section of it (ground on one side of fault moving quickly East, ground on the other side moving quickly West for example)