I've only observed that we haven't observed other observers.
I'm not asserting that there aren't some other observers out there, rather that if you take any typical quantitative form of measurering the universe, such as "mass" or "volume", then the ratio of observer to universe is so small that it would suggest observers are a fluke. Incidentally, this led to the consideration of how to quantify an observer in such terms, which led to my thoughts about what an observer really is.
I think I just spotted a strong hint as to why we thought about observer frequency differently:
...then who would be the only ones to be viewing "miraculous" conditions that allow them to survive?
You seem to hold as common to all universes that "survival of the fittest" will always successfully produce observers. Presumably under any laws of physics. Was this an intentional priori?