It's hard to say exactly since we haven't detected life on exoplanets, and don't know yet how common it is, but just looking at this star system alone, we appear to inhabit an extremely interesting planet if you're a scientist interested in natural life-forms (both plant and animal) and geological processes. All the other planets in this system are utterly lifeless and barren as far as we can tell, and certainly don't have the diversity of ecosystems and climates that Earth has. The problem with this planet is all the humans ruining it, so I'm a little surprised some aliens haven't decided to wipe out the human pests so they can preserve this planet as a sort-of nature museum. That leads me to believe that the number of alien civilizations out there that have achieved not only spaceflight, but more importantly interstellar flight, is vanishingly small or even non-existent. It could very well be that there's no actual way of going faster than light-speed, so civilizations simply don't bother much with it, except maybe trying to visit their nearest neighbor stars (something we're still quite far from achieving), so if interstellar-capable civilizations do exist, they could be so rare that none have been able to travel here and find us.