There is an argument that "the phenomenon" is ambiguous and fleeting. The elusive apparitions act with intent and even a sense of humor, or so say many of those who believe they have met the UFOs, Bigfoot, and similar oddities up close and personal.
My friend tells me if there are such goings ons, the instigator simply refuses to be corralled. They say it's like a soap bubble drifting on the breeze, colorful and attracting our interest, yet disintegrating under the very grasp which tries to contain it.
The sights and events often interpreted to be related to UFOs and similar reported phenomena, some suggest, must surely all be from the same mold. This would account for its elusive nature and an overwhelming lack of confirmed physical evidence, even as cost effective technologies have advanced which would make the collection of hitherto absent evidence all the more feasible.
Such theories of an intelligence behind an overarching and elusive "phenomenon" teeter on the edge of subjectively assigning definitive characteristics to apparitions not yet shown to so much as exist, at least not "exist" in more commonly accepted definitions of the word. Some would argue therein lies the rub, and perhaps they are correct. Maybe further knowledge of UFOs and things that go bump in the night indeed lies in the realms of the esoteric and traditions passed down among indigenous populations.
If that is the case, however, they must also take responsibility for understanding they cannot expect those who prioritize evidence-based research to embrace their assertions on faith alone. They must effectively demonstrate a specific difference between their chosen endeavors and searching the snow on the television screen for patterns of intelligence. If there is a difference, it should be demonstrable.
If knowledge of the "phenomenon," "other," "visitors," or whatever labels one chooses to project upon it, is more likely found in monasteries than science labs, the scientist trying to simultaneously sell both ideas to the public - and funders - must come to terms with the dilemma. At the least, it is unreasonable to take the role of a persecuted Copernicus, suggesting those who argue alternative views will not accept your evidence, when your argument advantageously relies upon the notion your white whale leaves no evidence when convenient. It can't be both.