The concern for asymptomatic spread is coincident with the concern about aerosol particles. This is because coughing or sneezing are symptoms.

The medical culture also has a bit of a problem with crying wolf---the community has to take care not to do so because randomly changing things can easily cause more damage than it prevents. In particular, the community tends to want to avoid prescribing major behavioral changes without good reason.

Do you remember, say, roughly this time last year here on HN? Hydroxychloroquine was the biggest topic in any COVID discussion. And "why aren't the stupid, rotted, insane medical community providing a cheap, known-safe medication as a prophylactic to everyone?" was the question everyone here was asking. After all, there was the distinct possibility that it could help.

Turns out that the supply was constrained, that it has side-effects, and that it doesn't work. Yay for the medical community, right? Everyone celebrating the success of science? Apparently not: "Medical culture has a severe problem with confusing 'absence of evidence' and 'evidence of absence', and the cost-benefit tradeoff...." But as soon as the ongoing, large-scale trials started dropping hydroxychloroquine from their protocols, the issue disappeared, with no admission that anyone had been wrong.

You are absolutely right that "scientific consensus changes all the time, and no stigma is (or should be) associated the work on the earlier, less accurate model." And yet it does: their earlier assessment is "insane"; it represents "systemic cultural rot".

Your Axios link gives me a 404; do you mean "Surgeon general defends reversal on face mask policy (12 Jul 2020)" (https://www.axios.com/surgeon-general-reversal-face-mask-d38...) or possibly "Where the science stands on using face masks against coronavirus (25 Jun 2020)" (https://www.axios.com/coronavirus-face-mask-science-e9df446b...). The latter article points to:

"Assessment of Fabric Masks as Alternatives to Standard Surgical Masks in Terms of Particle Filtration Efficiency (17 April 2020)" (https://www.medrxiv.org/content/10.1101/2020.04.17.20069567v...)

"Association of country-wide coronavirus mortality with demographics, testing, lockdowns, and public wearing of masks (Update June 15, 2020)" (https://www.researchgate.net/publication/342198360_Associati...)

"CDC to make updated recommendation on masks (22 Jun 2020)" (https://www.wwlp.com/news/health/coronavirus/cdc-to-make-upd...)

"Physical distancing, face masks, and eye protection to prevent person-to-person transmission of SARS-CoV-2 and COVID-19: a systematic review and meta-analysis (27 Jun 2020)" (https://www.thelancet.com/journals/lancet/article/PIIS0140-6...)

"Community Use Of Face Masks And COVID-19: Evidence From A Natural Experiment Of State Mandates In The US (August 2020)" (https://www.healthaffairs.org/doi/pdf/10.1377/hlthaff.2020.0...)

That is (a) exactly what I am saying, and (b) actually a little later than I can date the change---I've previously seen (and posted, IIRC) scientific discussion in mid-April to May about the changing consensus on transmission and mask effectiveness.

When you write "it's not a coincidence that this is the _third_ distinct (and often mutually-contradictory!) excuse I've heard on this thread", you do realize that there are multiple people involved in this thread and that some of them are simply wrong. But of course I would be saying that because I'm just making excuses and covering up rot, trying to cover up that everyone except the genii software engineers here on YN are complete idiots.