So they dug into the fundamentalist/evangelical
belief system to figure out why, and quickly realized that - short
version - quite a numbers of particulars inherent in a literalist
Biblical worldview just didn't really allow for the possibility of
extraterrestrials.
Literalist Biblical Believers don't allow for the possibility of extraterrestrials because of the implications that it carries.
When the movie Prometheus came out, Evangelicals went Crazy. They attributed the movie to Satan because it destroyed belief in the heavenly reward. Same with JWs. It destroys the promise by Jehovah that he gives everlasting life.
In the movie, David- the AI Robot asked the question to a human;
"Why did you think your people made me?"
The answer by the human was; "BECAUSE WE COULD"
David the AI replied;
"Could you imagine how disappointed it would be for you to hear the same thing from you Creators!"
The implications being that humans were created by other mortal beings in the Universe with no purpose in mind.
https://www.youtube.com/watch?v=jRa_xmJ4zXg
https://www.youtube.com/watch?v=SNm2AvrkE4w