Because the universe around us is unreachable, for a long time coming. It simply does not matter to our daily life that we are insignificant. We can observe, explore and expand knowledge. But never touch the surface of any other planet or feel the warmth of another star. Your neighbor matters more to your life than the Andromeda galaxy.

Not even the closest star changes or affects life on Earth in time scales relevant to us. For all intents and purposes we are an isolated microcosmos, save maybe some astronomic catastrophes unlikely to happen within humanity's span of existence (which isn't even a single million years yet).