I read the logic as something like Timeless Decision Theory. If you reached this conclusion and planted this evidence, there is a reasonable chance that previous actors in similar situations did so as well, and given enough previous actors, you should see the results. Since you don’t see those results, either there haven’t actually been very many previous actors, or something else about your assumptions is invalid. In either case, the logical basis of the Great Filter conclusion has been drastically weakened.
I read the logic as something like Timeless Decision Theory. If you reached this conclusion and planted this evidence, there is a reasonable chance that previous actors in similar situations did so as well, and given enough previous actors, you should see the results. Since you don’t see those results, either there haven’t actually been very many previous actors, or something else about your assumptions is invalid. In either case, the logical basis of the Great Filter conclusion has been drastically weakened.