Why do you think that explanation is particularly probable out of all of the other possibilities? It seems more likely that society would consider actions strange if the actions have justifications that most people don't understand or agree with, and they don't succeed in masking their judgement.
I don't follow your thinking here. Isn't it routine for there to be multiple possible explanations for human actions, in the absence of complete knowledge?
"Why did X have an omelette for lunch?" Many possible, non-weird explanations.
To the contrary there is very good evidence that we pull arbitrary explanations whenever needed. See Gazzaniga's split brain experiments where people gave all sorts of reasons when asked why they did something and just could not know.
I don't think either of your "possible explanations" are borne out by the evidence, but then there are a dozen other explanations that are both more plausible, and whose truth-potential is not dependent on whether they make sense to you personally.
I think that they do not have an exact reason and measured it and seen it happen is the surprising bit. Anything else is a good guess. Of those, people have plenty.
This speaks volume on how human can rationalize any phenomenon. When faced with a unexplained event, we all try to rationalize cause behind it even if there's not the real cause.
If it smells like it doesn't quite make sense, the most likely explanation is that it doesn't make sense and they are spinning a narrative that suits them.
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