I'm well aware of the fine-tuning arguments. Again, that applies to life as we know it. The truth is we have no idea what might exist and how it might exist beyond a handful of planets in our own solar system. Even then, we are unclear about life in just our own solar system.
Well all these speculations about life on other planets is about life as we know it. They always look for the things on other planets that life as we know it requires. Life as we know it is any kind of life that exists on earth. We don't know of any other kinds of life. Life as we know it hasn't been found anywhere else because it literally can't survive anywhere else.
Someone mentioned microbial life being seeded to other planets through asteroids. Logically the moon should have some type of life on it. If not by asteroids then by the manned and unmanned trips carrying tons of microbes. But it doesn't because anything living is killed once exposed to cosmic radiation, solar radiation, gamma radiation, cold, heat or whatever other hazard we encounter once we leave the womb of earth.
Life as we DON'T know it exists nowhere right now except in our imaginations. Kind of hard to argue with imagination.