This "positing" of supernatural beings, and variations on the theme (e.g. 'people want to believe that something is in control of life, and so posit a supernatural being to cool their anxiety') seem like instances of trying to be too intellectual, and ignoring an obvious fact: that people *see* and *talk to* supernatural beings. They have since the beginning of recorded history, and probably before. We can argue as to whether they are creations of the mind, or objectively real (or on the spectrum between), but there is no 'positing' required. Perhaps for left-brained researchers who don't have the ability to interact with the 'other', but not for a large amount of people.
"There's an old saying; just because you're paranoid, that doesn't mean they're not out to get you. I have my own variation: just because you're insane that doesn't mean that things aren't slipping in unnoticed through dimensional gateways..." ~ Christopher Knowles (h/t to The Daily Grail for quote.)