I think you're the one ignoring the theory. Fermi's Paradox recognizes that there is no credible evidence for the existence of extraterrestrial civilizations despite the high probability that they exist. So those who answer "no" to this poll aren't ignoring the theory, in fact, it's exactly the opposite. Part of the reason for this belief in a lack evidence in extraterrestrial civilizations, and by extension visits to Earth, is that the vast majority of it is based on eyewitness testimony. Eyewitness testimony is notoriously unreliable because memory and individual perceptions can be manipulated and heavily impacted by bias. So until there's actual evidence that can be substantiated, I'm going to default to the argument that Fermi's Paradox makes and that you dismiss: that there should be extraterrestrial civilizations but there's no proof yet.