Most people believe in ghosts, if you get them to be honest. Aliens probably aren't far from that. We're just kind of hard-wired to believe that the further you get from our day-to-day life, the more likely monsters are there.
Ghosts, on the other hand, are pretty far out there. We have no evidence or even any working thesis of how the consciousness of individuals could persist in some ethereal form after death.
It’s weak, I believe, to operate on a platform of talking for strangers so confidently.