I can't recall the exact quote, but roughly paraphrased: In the absence of compelling evidence to the contrary, more straight-forward physically plausible explanations have a distinctly higher probability of being true than do fantastically complex ones. We just don't have any compelling evidence yet for sentient interstellar travellers, let alone invaders.

@MikeInBatonRouge in other words it's more likely that humans want to harm humans than aliens do?

@FrayedBear something like that. One of the hallmarks of a conspiracy theory is its convoluted complexities. Maybe the appeal is that people like to feel they are part of a complex secret knowledge that sets them apart from (and above) the "ignorant" masses of mainstream society.

Didn't mean to suggest that YOU are a conspiracy theorist, or anything. Complexities DO exist in the cosmos, to be sure. But when trying to understand reality, one starts by testing the most straightforward theories first.

@MikeInBatonRouge I asked a question & didn't promulgate a conspiracy.

Yeah, temporarily, but broadly shedding and spreading virus in the meantime. They have already tested and reported that COVID-19-positive but asymptomatic people spread the virus just as much as sick people.