Keep in mind SETI is only searching a portion of the carrier wave band width, and our own carrier waves have only hit a very small portion of our galaxy, forget the universe.
The only real negative implication if we are alone is that makes habitable planets more rare. We need to find habitable planets for the long term survival of the species, eventually this place will no longer be able to sustain us, known natural processes will lead to that. If we don’t have self sustaining chunks of our self elsewhere by then nothing else that we’ve done means anything. The positive implication is no competition.
Since it would take THOUSANDS of years just to reach the nearest star system, you won't find many volunteers for that settlement mission. Oh and imagine the horrible depression that would set in when after THOUSANDS of years and countless generations, they reached the closest star system only to find out every planet was uninhabitable and would have to RETURN back to earth.