[joe_the_user]

Maybe, just maybe, the fact that we're not seeing much is actually indicative of a fairly rich sea of life in the galaxy, communicating point-to-point with each other.

Except for the small question of how those many civilizations would have found each other in the first place.

[scrumper]

True. But nearer the galactic core where stars are so much closer together? SETI might have a much higher hit rate there. We are in kind of a backwater out here. It's easy to forget about the big city when you're out in the sticks.

It's not very likely though. Occam's Razor alone suggests that the reason for loneliness is that there aren't a plethora of civilizations all talking to each other over narrowband channels. And we'd be very unlikely to pick up the omnidirectional beacon of a lonely civilization way out here anyway.