I think that the world has depression. Ever day, we are constantly bombarded with news of terrorism, diseases, natural disasters, and incompetent politicians. These are very real problems, but the real problem is that no solutions are being reported alongside the issues. From my perspective, the world seems to have accepted the grim nature of its existence and trudges through each day without any hope of redemption. Truth is, many of the world's biggest problems CAN be solved, but the world doesn't seem to know that. We've stopped believing that things can improve because we see very little evidence of that improvement.
THIS is why spaceflight is important. In fact, I'd go out on a limb and say that expanding into the Solar System is one of the single best things that can be done for the world. Take the tried-and-true example of the Apollo program. In 1969, the United States was at war and under constant threat of nuclear attack. Yet people looked at the space program as evidence that a greater future was in store, that there was light at the end of this long, all-encompassing tunnel. Human presences on the Moon and Mars will not just be technological achievements, but monuments to the fact that seemingly impossible problems can be overcome. If we can build a city on Mars, why not cure cancer, or develop nuclear fusion, or ditch fossil fuels? It's a pattern we've see throughout history, from the American Revolution to the transcontinental railroad, then from NASA to the Internet, and today SpaceX and Tesla. They serve as monuments to that desire of a better future, a testimony that our hope is not in vain. It's an empowering thing, and it's what humanity needs the most.
That's what people who say things like "fix Earth problems first" get wrong. In order for Earth's problems to be fixed, we have to believe that they can be. And it'll take such an incomprehensibly challenging effort like human spaceflight to make people realize that our terrestrial problems may not be so hard to solve after all.