My interpretation, which I'm only 90% sure of, is that if we weren't early we'd be dead, since an earlier civilization would have colonized Earth for their own

My interpretation, which I'm only 90% sure of, is that if we weren't early we'd be dead, since an earlier civilization would have colonized Earth for their own purposes. So seeing no one else out there is to be expected. It's a bit like how it's NOT weird that we happened to evolve on a planet that is so extremely favorable to our form of life.