Most of the people making either claim are highly religious (as in, Christian). Automatically, the “alien” paradigm threatens their religious beliefs since most don’t see room for aliens in the Bible. If these really are extraterrestrials, then where does Jesus fit into all of this? Why aren’t aliens mentioned in the creation narrative?
In contrast to the alien explanation, the demon and government explanations both offer “safe” alternatives. After all, both of these explanations are not only compatible with Christian belief, it’s easy to imagine that “the return of Jesus” will simply solve these problems.
If these are demons then great. The Bible talks about demons and they are clearly inferior to God/Jesus. If it’s government, then no problem either. It too, will be flung to the wayside during the “End Times.” Hence, these are “safe” alternatives for those looking for comforting alternatives.
Wishful thinking aside, there is little reason to believe these are government or demonic presences. For one, the abduction phenomenon dates are far back as at least several decades. The idea that the government had the sort of technology to conduct these sort of covert home invasions during the 60’s seems absurd. And both government and demonic explanations are difficult to square with the whole hybrid phenomenon.
Whatever these entities are and wherever they come from, they can’t be boxed into either of these “easy” paradigms.