Here on our lovely little blue marble of a planet, nearly all sentient beings believe violence is a legitimate problem-solving technique. Is that mindset a universal truth? I don't know; and neither does Hawking. His educated guess is undoubtedly more well-informed than mine, but it's a guess all the same.
Besides, none of us are getting out of here alive anyway. If capitalism and its rape of the planet doesn't kill us, something else will. I'm sticking with my long-held vision of being struck in a pedestrian crosswalk by a stolen car. How's that for glamor? Bring on the big scary monsters from outer space, Stephen, 'cause I'm ready.
It seems to me, shouting into outer space via transmitted messages makes just as much sense as staring at it via telescopes; and I'm presently busy listening to it, albeit indirectly, via the Berkeley Open Infrastructure for Network Computing (BOINC) and the Search for Extra-Terrestrial Intelligence at Home (SETI@home). Apparently the best we can do at this point, to learn about the universe at large, is mimic the methods of eavesdroppers or peeping Toms.
=^..^=