Elon Musk and the Value of Localism or What We Should Do Instead of Going to Mars

Elon Musk really wants to establish a colony on Mars. One reason he keeps coming back to this the idea is that he claims it is the only way to prevent our eventual extinction. But is this really the best way to avoid the problems he fears? If we're really interested in increasing localism (which as strange as it might sound is what a Mars Colony is) are there better ways of achieving it if we focus on a better identification of what we're trying to prevent? And does this insight apply at scales much lower than preventing x-risk?