My response to the smoking lesion paradox is that longer life is not associated with not smoking, but with not smoking that is done for reasons other than to avoid death. Likewise, for the extraterrestrial signal paradox, survival of civilizations is not associated with sending radio signals, but rather with sending radio signals for reasons other than to ensure survival.

If you're going to go with a partial correlation, then 20% of the correlation between smoking and death is caused by the lesion and 80% is caused by something else (such as the fact that smoke isn't good for you).

In the analogy, 20% of the correlation between no radio signals and death of a civilization is caused by something destroying the civilization before it gets to produce signals, and 80% is caused by something else. That doesn't make any sense.