Strongly disagree that the specific kind of intelligence that builds spacecraft is not unique to our planet in any way follows from the quite reasonable belief

Strongly disagree that the specific kind of intelligence that builds spacecraft is not unique to our planet in any way follows from the quite reasonable belief that life is probably not unique to our planet. The latter belief is supported by a lot of evidence: the molecular machinery of our kind of life is pretty common, and the chemistry that drives it appears to be robust and nothing special. To get a sense of how special the kind of intelligence that builds spaceships is, however, consider that every complex feature of organisms, from insect societies to wings to eyes, has evolved many, many times, all independently of one another. Intelligence of the kind that builds spaceships, on the other hand, has evolved exactly once in the history of our planet, and appears to have been the result of a runaway mate competition and mate selection process in our social primate ancestors. There was certainly no material advantage to having a brain big enough and well enough designed to build spaceships when you were busy scrabbling for food (a feat that a huge range of unintelligent organisms, including unintelligent social organisms, manage reasonably well.) So it is quite plausible that there is life all over the place in the universe, and intelligence almost nowhere. Just because we can see the advantages of intelligence doesn't mean there is a clear evolutionary path toward it, and the history of life on Earth suggests in fact that the path to the kind of intelligence that builds spaceships is extremely narrow and twisty.