A lot of people are bothered by it. There's not much we can do about it yet - we've done what we can with the crude methods we have available to look around, bu

A lot of people are bothered by it. There's not much we can do about it yet - we've done what we can with the crude methods we have available to look around, but we're severely knowledge-and-tech limited in ways of checking. It leads to a lot of philosophical hypothesis though, including the idea of a "great filter", which makes a lot of people extremely worried. Hell, the richest man in the world, and one of the most powerful, is supposedly motivated by a desire to get off-world to avoid a future disaster. I haven't heard him speak specifically about lack-of-aliens as a reason for worry, but I'm sure he's come across that argument before.