My point is that we all interpret what little evidence and draw our conclusions on this subject based upon our favorite assumptions.
One assumes that nothing living exists beyond the material universe and so the evidence (again, if there is any at all) is evaluated on this basis. Another is skeptical of the materialist claim and considers the bigger picture presented by some sort of spiritualism and so possible explanations of this nature become a possibility.
I understand your argument, but I think it is demonstrably mistaken.
Firstly, science follows the philosophy of methodological naturalism. That is, it does not exclude the possibility of the supernatural, or the spiritual; it simply notes that these are beyond the capacity/interest of science to investigate. An analogy would be that a chef can be expert in culinary skills yet have no interest in the decompression regime for a scuba diver. This is not an assumption, but a practical decision in defining the field of investigation.
Secondly, several scientists have taken an interest in phenomena whose origin and character are uncertain. They have not assumed they are natural, or non-material. They have simply investigated them to clarify, as far as possible, their character. Without any significant exception this has demonstrated that they are material. There is a strong motivation on the part of those scientists with a hunger for novelty, or deeply held religious beliefs, or just plain old mavericks, to turn the scientific world upside down by lifting the curtain and exposing the non-material behind it. Thus far, all we have found is a charlatan from Omaha, Nebraska.
I spent considerable time in my youth investigating clairvoyance, telepathy, telekinesis and spiritualism (in a rather amateurish, but nonetheless committed way). So I certainly never assumed that nothing living exists beyond the material universe. If anything my bias was too strongly inclined the other way.
Let us restrict the discussion to UFOs - that's relevant topic on this thread. I am always willing to examine my position in order to identify false premises and hidden assumptions. So, I would welcome you identifying for me which assumptions you think I am making that prevent me from giving
further substantial consideration to non-material explanations. (To put it another way:
been there, done that, got the T-shirt.)