Screw Mars. Spend all that money on making it nice HERE. We have the means. We have the tech. We could have a star trek utopia right here... Free education, opportunity through small businesses, cheap housing, plentiful energy. We could have all that right here if we just put a smidge of effort into it.
Well, we could do that too.
But us fucking up the planet isn't the only scenario that might cause planetary extinction. Do you remember what killed off the dinsaurs?