We are the first civilization to get to using electromagnetic communication.
We are very far away from the few other civilazations.
We are not listening carefully enough.
We are the only civilization that hasn't destroyed itself.
We are the only civilization that the berserker robots haven't destroyed.
We are being protected by another race from hearing the chatter.
We are the only civilization that has not yet turned inward to gaze at their internet navels full-time.
We are in a universe simulation that only has one planet inhabited by technology-using life.
We are being contacted but they only contact people on back roads.