I won't attempt to convince you with philosophical arguments, as there are none. Whatever philosophical argument I might make, someone will just counter with ni

I won't attempt to convince you with philosophical arguments, as there are none. Whatever philosophical argument I might make, someone will just counter with nihilism. The only argument is biological. It's the same reason nihilists continue to live. Survival is an essential trait of all species. Ultimately it can be argued that all of our advances had that purpose in mind. Spreading humanity far and wide helps to satisfy our need for survival. You might argue that it doesn't affect you, as by the time we colonize other systems you will be long dead. But when you produce offspring, you care less about your own survival than the survival of your offspring. That is to say, your need for survival is transferred to your offspring. As long as they survive, you survive in the form of the genetic material you pass on and the knowledge you have endowed upon them. Presently, the greatest danger to humanity is self-annihilation. Making the transition to an interstellar species is imperative in order to eliminate this danger.