The evidence is everywhere. There are bodies (In fact, Greer happens to .. Um, own one? I guess.) Footage, eye witness accounts, even a government program or two dedicated to it.
I find it hard to believe that it gets lumped in with Ghosts and Angels.
A lot of people will look at some blur at the scene of a car wreck and say it’s proof of ghosts and angels yet we are deluged with evidence of Aliens and it’s laughed at.
Proof ? Not until you’re face-to-face with an alien can there be proof anymore. with CGI and stuff it’s simply never going to happen.
Again, show a single piece of physical evidence, even in the the archaeological record and perhaps I'd agree....
God, Angels and such are a belief....no physical evidence is needed or required..