The universe, being some 10,000 million years old, is a very long time compared to the time that we humans have existed - a mere fraction of that time.
So, is it not plausible that those beings that have the technology and the biological make-up either to get here and/or get here and survive in our climate, could have missed us already? Might we not miss them in the grand scale of time?
As usual, Hawking is right. Perhaps when you and I are ready to travel to the nearest planet capable of harbouring life, would we, in fact, still be human? I think not. What ever comes along is going to be vastly different and somehow, I think, superior in many ways that will probably not benefit our race.