But that's not the mechanism at issue. The mechanism at issue is they don't get bought at the hardware store in large quantities, the hardware store doesn't order as many to restock, so their direct supplier isn't willing to pay as high a price to the manufacturer so more of the production capacity is available for other uses.
The general public are not the Borg, they don't act with uniformity of purpose. If you tell the public "Don't buy these respirators from the hardware store" and 70% listen, then the other 30% will still buy out all the stock because demand is much higher than supply right now. You can't solve the problem at consumer level.
And they respond to demand signals when making that decision.
Slip a super-hard, super-thin backer underneath it, then cut? (Aluminum probably being the best scenario, as far as industrial metals go)
In the US, paying thousands of dollars for healthcare, hospitals can absorb the cost of masks increasing from 1 cent to 1 dollar.
There is a shortage, so people in risk groups (elderly people and people with respiratory problems) or people close to those at risk cannot get them.
Second, it increases the price, which caused incidents of people stealing them from hospitals to sell them.
So, in a way, it is more practical then you think.
Not to mention that if it really gets dire, like in Wuhan, then the image becomes less hilarious. (That's why there is the study)