Yeah, but would we want to meet other life forms, intelligent or not? Nature breeds violence not peace, rewards the primitives for their aggression. Here on Earth humanity is feared by all animals as the most significant predator. Creatures on other planets would not share that fear and the loss of life from even coming into contact with the dumb could be significant for the short term.

And unlike what some hippies may think, aliens will almost certainly be blood thirsty savages. Because peace is an anomaly! Nature kills the weak and nature kills the peaceful! Civilization is a human invention, built out of our need to conquer and rule what we conquer. Its development into what we have here, something with aspirations of peace is a fluke.

I say the odds are, we are better off alone, for if we meet another civilization to them we will either be prey or competition.