I see it stated all the time, but whenever I ask why, instead of a substantial argument, I get downvotes or "isn't it obvious?" or some thinly veiled "how dare

I see it stated all the time, but whenever I ask why, instead of a substantial argument, I get downvotes or "isn't it obvious?" or some thinly veiled "how dare they debunk something I wanted to be true.". The plagiarism accusation is interesting and should be resolved, but isn't evidence of misinformation or evidence that they are less reliable than [no known alternative] suggested by critics.