Quite the contrary. As we have just observed, Planet Earth lives in a shooting gallery, its interior is a species-killing bomb waiting to detonate and humanity itself is capable of species-wide annihilation, including self-annihilation. We have enough nuclear weapons to destroy ourselves many times over, and the genetically-engineered plague viruses could also end civilization as we know it. We can never spend too much time planning for catastrophe-prevention and consequence-management.
Robert Heinlein said that “earth is too small and fragile a basket for humanity to put all its eggs in.” Many scientists have argued that for humanity to survive the next millennium, we must spread our species into space—onto other planets.
If nothing else, the Mayan prophesy of 2012 should be viewed as a profoundly important wake-up call, the ultimate cautionary tale.