You're implying we don't have any information at all. We do.
Even if you argue is it's limited, to our knowledge bio processes outside of earth has been zero. Whereas, non-bio chemical processes is greater than zero. So now people want to bet on that it's bio??
Milky Way contains on the order of half a trillion star systems. Would having, say, a million planets carrying some form of life in our galaxy alone qualify as “rare”?
To be fair, I wouldn't consider that rare. When we talk about life, we usually think in terms of are we alone. If there are a million planets with life, life isn't rare, regardless of what percentage of planets have life.