Before seeing any evidence, we should indeed expect that life has high density in the universe. We just have enough data to rule that out. More generally I think UDASSA is probably the best framework for approaching problems like this, and it would hold that, in situations where our existence is contingent on an anthropically-selected unlikely event, we should still expect that this event is as likely as possible while being consistent with the evidence. So 10^-40 likelihood origination events more probably than 10^-400 likelihood events.
Before seeing any evidence, we should indeed expect that life has high density in the universe. We just have enough data to rule that out. More generally I think UDASSA is probably the best framework for approaching problems like this, and it would hold that, in situations where our existence is contingent on an anthropically-selected unlikely event, we should still expect that this event is as likely as possible while being consistent with the evidence. So 10^-40 likelihood origination events more probably than 10^-400 likelihood events.