People who read the news and get “masks don’t work” out of it should not be using masks until there are enough available for professionals who need them.
How about I meet you half way and call it an "incompetent noble lie".
https://docs.google.com/document/d/1HLrm0pqBN_5bdyysOeoOBX4p...
Perhaps there’s concern that if CDC or others advise people to use homemade masks, people who actually do need N95 masks (e.g. severely immunocompromised) will think that works for them?
Edit: there’s also the moral hazard aspect to consider: if people think wearing homemade masks is enough to protect them, they’re probably a lot more likely to ignore quarantine or social distancing. If the masks aren’t 100% effective and are used wrong, that could be worse than just staying in and social distancing.
A blanket statement against all types of masks without qualification.
However the CDC also says if you "think you might have COVID-19", you should "wear a facemask" "to help protect other people in your home and community." "You may need to improvise a facemask using a scarf or bandana."
https://www.cdc.gov/coronavirus/2019-ncov/if-you-are-sick/st...
Seems to me we should all assume we "might have COVID-19" and therefore follow CDC's advice: wear a facemask of some kind to protect other people.