>In the absence of proof, how is the contemporaneous assertion "[AIDS] was the product of biological weapons experiments conducted by the United States" any less reasonable?

Because that claim is nonsensical and defies common sense, whereas the idea that an accidental infection took place is entirely reasonable and requires no leaps of faith whatsoever.

>At least one of those papers was written by a Wuhan Institute researcher.[1] Is that supposed to constitute circumstantial evidence that implicates the institute?

What gave you the impression that this particular paper is the reason for the theory? This institute works extensively with bat coronaviruses, published over 40 papers on the subject, had teams doing field work in caves where they came in direct contact with bats, stored many samples on site, have had systemic deficiencies in their safety and training, and were in Wuhan, the ground zero which is hundreds of kilometres away from where the bat populations likely to carry the virus that SARS-CoV-2 mutated from actually live. All of this, while being insufficient to say anything definitive, together points to accidental release as a completely legitimate origin theory.

The US government of course may have a lot more information, leading it to believe that a lab accident is not just plausible, but likely. Or they could be lying and/or engaging in dirty politics. That too is a legitimate theory.

> not to mention substantive evidence (e.g. pangolin intermediary), of it emerging precisely as claimed by the consensus hypothesis.

Consensus hypothesis is very much subject to change. For example, the wet market origin was a significant part of it, and just a few days ago China officially said it now no longer considers that to be the source of the patient zero transmission, but merely a site of a super-spreader event. The pangolin theory was dismissed as recently as a month ago, and now there's some new evidence in its favour. Nothing we're talking about, including accidental release from a lab in Wuhan, remotely crosses into conspiracy theory territory.

>Is it possible it leaked from the Wuhan Institute? Sure. Just as it was possible the U.S. manufactured AIDS as part of its extensive biowarfare program.

What do these word games add to an adult discussion? 'Possible' means nothing. The difference between these, much like the difference between a one in ten and one in a billion chance, is how possible.

>They're both still nutty theories, it's just that one has the benefit of hindsight and distance filtering all the contemporaneous coincidences, while the other still seems intuitively plausible without the assistance of analytical thinking to clear the brain fog.

Again, analytical thinking, if you do choose to apply it, would lead you to see the clear difference between a conspiracy theory and a legitimate theory without sufficient proof. Here we have the latter, since accidental release would be logical, plausible, contradict no firmly established facts at all and would require no leaps of faith at all (unless you consider the idea that the Chinese dictatorship tried to obfuscate and cover up the truth about such a theoretical accident).