The link you provided before was not the entire book, but just samples. What I saw of it looked pretty bad.
So if they are not pseudoscientists spouting mumbo-jumbo does it follow that their hypothesis is correct?
Here's
a review of the book that concludes:
Here's
another one (I'm just going in line of the google results of "rare earth criticism") that contends that it was a decent theory until recent results in discovering so many extra solar planets have shot it down.
The third one is on a site called SETIleague and obviously not very warm to it either:
The fourth hit was
the wiki article, which includes a number of different criticisms of the theory.
And you keep setting this up as the only alternative to the "we are probably unique" position. It is not.
The fact is, we don't know how common ET life (microbial or complex) in the universe is. There's no reason to think that conditions are so exceptional here that there is something special or unique about the Earth. I reject the assertion that ET intelligence is probably common (again, see my repeated issues with the fact that terms like "common" and "rare" are relative), but I also reject the assertion that we are probably unique in the galaxy.
I think the rare Earth hypothesis basically describes how complex life on Earth came about. It may or may not be a good description of what was required for we humans to arise. Even if it is, the authors are wrong to assert 1) that these are the only conditions under which intelligent/complex life could arise and 2) that these conditions aren't likely to occur elsewhere in the galaxy.
And this is pure speculation. It's little more than an opinion.