Ireland grew much more than potatoes. It is a fertile land. The British claimed all of the other food. The farmers were very poor and worked very hard but could only keep the potatoes. They also cut up the land so that the sharecroppers had smaller and smaller parcels. Taxes were high. All profits of their labor were taken from them in rent and taxes and most of the food that they grew was for the Brits. The Salvation Army did a lot of good and tried to help. The information that you reference seems like pure propaganda by the Brits. My family immigrated to the US from Ireland. Most of them abstained from drink altogether. They prospered here and brought over most of their families who were starving.