There are an aweful lot of people in power who would lose that power if "civilization" were to "implode" and powerful people don't like to lose that power. That pretty much sums up why "civilization" won't "implode". Imagine the oligarchs losing their control of the global wheat or rice supply. Those companies have written procedures in place for ways to avoid losing their power over those industries. For example, the CIA even has a Zombie Apocalypse Plan.