It's hard to reason when you only have one data point, but there are very good reasons we have only one data point so that alone rules out nothing. The universe could be crawling with life and we'd have no way to know it because it's so big.

What we Do know is...

1) The chemical precursors to life, organic compounds, appear everywhere, even in the interstellar medium. The raw material is there, and its been there ever since the beginning.

2) We know life can exist in very hostile environments even here on Earth, and we know now the universe generates a lot of different kinds of environments that might be just as hospitable to life as some of the grimmer places on our own world. So potential habitats not only exist, they are common.

3) Our one data point, Earth, is very encouraging. Life appeared very early in earth's history, in an environment that today would be considered toxic for most life forms. This suggests it is very easy for life to arise.

However, over the years, as I have become more optimistic about ET life, I have become more pessimistic about the possibilities of intelligent life. I still believe it exists, but I also believe it is extremely rare. Intelligence doesn't seem to be a survival trait, and it may be devastating to the ecosystems it inhabits. Although I don't accept the logic of the Fermi Paradox, there are other good reasons to believe ETI is very rare. And of course, not every intelligent species would have the ability or desire to communicate with others. I know this will not go over well in a board dominated by tech groupies, but I think high technology communications and spacecraft are extremely rare even among intelligent and technologically oriented species.

My WAG (based solely on my intuition!): There are between 10 and 1000 intelligent species in the Milky Way Galaxy at any one time, and they have an average lifetime of less than a million years. This means the nearest one is probably several hundred or thousand light years away, and with our luck, it has a biology similar to a slime mold, live under water, and developed a technology based on genetic modification of bacteria. We might not recognize each other as being intelligent even if we lived on the same planet.