It’s not arbitrary. Alien UFOs, Chem-Trails, and Flat Earth are obviously all generated from the same distribution of bullshit: ambiguous or misunderstood phenomena explained by positing a vast hidden conspiracy.
I'd prefer to speak about "evidence in support of/against" rather than "facts", which often conceals a presuming-the-consequent kind of fallacy.
> denial of science
Whether "science" is believed or denied by any particular person has no effect on whether or not extraterrestrial intelligence has or is visiting earth.
Demanding that "science" be believed is un-scientific. I am not drawing an equivalence between science and religion here, but pointing out that your argument is a super hand-wavey appeal to an inviolable "gospel". I'm old enough to remember when a theory like intra-galactic panspermia was regarded like canals-on-Mars.
In my view, ETI theories are lacking any credible evidence and this makes me sad.
And the facts are just ... released. It's the interpretation of the observations that are disputed. And unless you think they are all fake, the explanations that do not involve alien tech are non-trivial to say the least.
I'm not sure why you'd think there is any shared causal structure with flat earthers at all.