Hoarding masks would have been the sort of response that the author is railing against (a hoarded mask isn't doing anything to get R down), except that, being a

Hoarding masks would have been the sort of response that the author is railing against (a hoarded mask isn't doing anything to get R down), except that, being a free-market response, it would not have served the author's purpose as a parable extolling the wisdom of markets. Asking people not to hoard masks would have been no more effective than it was for toilet paper - I would guess less effective, in fact.