“If you were a health professional treating an immuno-compromised patient, you wouldn’t want to be breathing your micro-ecosystem into the patients face or anywhere else.”
Doctors and nurses encounter immuno-compromised patients virtually every day and they do not routinely wear face masks.
PS I think the REAL “missing link” in the discussion is that (assuming it’s accurate - I haven’t checked) as another commenter advised me, the CDC’s actual guidelines say that properly-fitted face masks DO provide a measure of protection FOR THE WEARER. This was conveniently omitted from the article that started this thread as it would have contradicted the position that masks don’t provide any protection, so there’s no need to buy them.