Except you have no idea of the relative probability of these events. Two of them have robots on them precisely because of the space-travelling, radio-communicat

Except you have no idea of the relative probability of these events. Two of them have robots on them precisely because of the space-travelling, radio-communicating species on the third. But we have no firm data on the likelihood of a random planet in a star's habitable zone being rocky, having an active core, and a slow enough rotation for a stable atmosphere. Nor for that matter the expected percentage of time that such a planet should be expected to be populated with intelligent life over the span of its existence. You're effectively saying, "Somebody else has discovered a swan. The only swan I've seen is white. Therefore, I expect that this new swan is white as well."