No, manufacturing magazines is not difficult. But, ramping up production to cover a short increase in sales is difficult.
The manufacturer may be at capacity of their production equipment and it would be a large investment and time to add capacity.
They may have only enough staff to cover pre-panic sales and it takes time to train new operators.
What do they do in a few months when the panic slows down, or worse, the Feds turn off the tap. Do they lay off workers? Do they scrap the new equipment they just purchased?
Not easy decisions.
What did I do, I planned ahead starting in 2010 and had been laying in inventory expecting the worse after the election. I figured there were too many sore losers in the race for president.