When a crop is ready to harvest, Farmers harvest. If a crop is intended to be shipped to restaurants, hotels, event centers & cruise lines and that demand is suddenly cut off, no farmer is going to spend the time and money implementing a radical emergency business re-structuring to set up the shipping and equipment necessary to send that crop elsewhere. Most plants go bad within days of picking if not stored or preserved. If the cost burden on farmers makes the crop worthless, they'll let it rot.
"just make alcohol" requires distillery infrastructure and shipping costs that most growers and distributors are simply not set up to do in a short term window required to save the crop.