Complete BS. The Influenza virus has been with us for decades. Nowhere in any of the literature dealing with that virus is there any mention of masks as effective.
This Wuhan virus is much smaller than the Influenza virus. So, if there is no evidence after many decades of research that a mask is effective against Influenza how is it effective against the much smaller Wuhan virus?
Interesting scientific study on that here: https://www.nature.com/articles/s41591-020-0843-2
Speaking of influenza, I have also asked those ardent mask-wearers on social media--"The flu kills, despite a vaccine. Why haven't you worn a mask previously? Why is COVID-19 different?"
I usually go on to point out that most people have likely, indirectly been a vector for the influenza virus, and that they've likely caused a serious hospitalization or death as a result.