Re: Suggestive, but nothing more
"We are therefore still alone,"
I think we'll always be alone since IMO our civilisation is a one off fluke. For it to arise a number of things
had to happen:
1) A planet with an enviroment for suitable chemical reactions to occur
2) Somehow the chemical reactions lead to a self reproducing system
3) Single celled life became multicell
4) Life had to make it out of water onto land (not much chance of fish building a spaceship) which was possibly helped by a large moon causing tides
5) Humans had to evolve - not a given especially if that asteroid had missed 65 million years ago
6) The industrial revolution had to occur. Again not a given - if there had been no coal deposits we'd still be riding around on horses with the most advanced machines being windmills.
7) The computer revolution had to occur.
I'm sure there are plenty of other important points in history that could have led to a very different outcome, but the point is - life evolving may or may not be rare, but a technological civilisation IMO is.