I for one hope we never encounter a civilization more advanced than we are. If they are at all militaristic and even a few hundred years more advanced than we are -- never mind millions of years more advanced -- we're goners.
I don't know about this rare earth stuff, either, having not read the book . . . But do we really know enough about life to say that advanced forms cannot evolve unless they have an environment just like earth's? I'm skeptical.
I used to think advanced life was probably abundant in the universe, but no more; the failure of the many SETI searches of the last few decades to turn up even one, argues strongly against it, IMHO.
So I'm with you, RW . . . NASA should change the focus from searching for life to exploiting and developing space near earth.
NASA should leave the search for life in the capable hands of RadioAstronomer and his crew. For them it's not a job, it's what they want to do.
Interesting comment, as I do believe that if "other life" is to be found, it might only come from our own planetary expansion.
But then again I live under a rock.
We have just barely scratched the surface. Only recently have we had the computer power and the front-end sensitivity to do it right. I have almost finished my upgrade of our system to look at 30 million channels instead of the paltry 3.1 million we have been so far. Also most searches have been in the "water hole" frequency range, which in MHO is a futile effort. So The project I am currently involved in is looking at about 3 times that frequency.