There's an enormous, distant, and almost unfathomable reason why getting ourselves into space travel is essential to the human race. The moment we can physically look back at our home, one tiny speck amongst trillions of other tiny specks, will be the moment we can tell ourselves "Wow. We're very small. Imagine what other worlds might exist in those other countless arrays of stars and planets. All these petty issues on Earth hardly matter when the universe is out there, beckoning us forward. Let's drop the crap that separates humanity, and show all known existence what we can do together."
Some respond to such an idea with "But doesn't that make you feel insignificant? Why continue living if it's pointless and daunting beyond comprehension?"
I respond with, "It took us billions of years to get here. Why ruin what little slice of consciousness we have? This is what our universe is, and this is what we can do. Now, let's explore, understand, have fun, and live it to the fullest extent. Plus, it's cool."