I think it's important to remember how empty space actually is, when taking this view point. For instance, an object randomly shot through the asteroid belt has near zero chance of actually hitting anything, and that's a relatively dense space. The Oort cloud, which is where a large number of the theoretically unknown comets live, is only about 5 Earth masses.
The bottom line is, pointing a telescope to a random spot in the sky is very, very likely to find nothing. Even with a billion comets and a billion asteroids and a billion stars.
The bottom line is, pointing a telescope to a random spot in the sky is very, very likely to find nothing. Even with a billion comets and a billion asteroids and a billion stars.